My name is Fahad and you can call me anytime. This is my blog about all i have learned in computer applications.
Chapter 1
Introduction to computer applications :-
firstly what is a computer ? it is a electronic device operating under the control of instructions stored in it own meamory.
There are five components of a computer and they are :-
1) Input Device
2) Output Device
3) System unit
4) Storage Devices
5) Communications Device
An input device allows you to enter data and instructions into the computer . An output device on the other hand does convey information from the computer to one or more people . System unit it is the case the contains all the electronic components of the computer that are used to process the data. storage device plays the role of recording or retrieving items to or from storage media. Communication device is a device that allows the computer to send and receive data and instructions and information to and from one or more computers or mobile devices.
Now lets talk about advantage and disadvantages of using a computer
There are many advantages such as speed , reliability , consistency , storage , communications
and disadvantages are as follows health risk , privacy risk , public safety , impact on labor force , impact on environment.
There are many types of computer
Personal computer :-
a personal computer can perform all of its input processing , output and storage activities by itself.
Notebook computer / Mobile computers :-
They are basically personal computer relatively small and compact in size so that you can carry it to place to place.
Mainframes :-
A mainframe is a large, expensive, powerful computer that can handle thousand of connected users simultaneously.
Super computer :-
Super computer is the fastest and most powerful computer in the world and they are capable of processing more than one quadrillion instructions in a single second.
Embedded computer :-
This purpose is a special purpose computer that functions as a component in a large product for example in consumer electronics , home automation devices , automobiles , process controllers and robotics , computer devices and office macines.
Networks and Internet
A network is a collection of computers and devices connected together often wireless by communication devices and transmission media
The internet is a worldwide collection of networks that connects millions of business , government agencies , educational institute and individuals.
Computer software :-
Software are also called program they ask the computer what task need to be performed and how they should be performed.
installing is process of setting up software with the computer , printer and other hardware.
A programmer develops software or write instructions that direct the computer to process data into information.
Chapter 2 :-
The world wide web :-
the world wide web or web consist of a worldwide collection of electronic documents
A website is a collection related web pages and associated items
a web server is a computer that delivers requested web pages to your computer
web 2.0 means refers to websites that provide a means for users to interact
A web browser or browser allows user to access web pages and web 2.0 programs
for example:- internet explorer , firefix , google chrome
home page is the first that is displayed upon opening the browser and web pages provides link to other related web pages . Downloading is the process of receiving information. a web page have a unique address called url or web address
There are two types of search tools first is search engine ( for example google ) find information related to specific topic and subject directory classifies webpages in an organized set of categories.
you can look for all kind of audio , video , images , publication etc through the search engine
There are thirteen types of websites around the world they are :- portal , news , informational business / marketing , blog , wiki . online social network , educational , entertainment , advocacy , web application , web aggregate , personal .
An IP address is a number that uniquely identifies each computer or device connected to the internet
and a domain name is the text version of an ip address.
in the world wide web a home page is the first page that a web site displays web pages provide links to other related web pages. downloading files from website is the way of getting an information
There are thirteen types of web sites they are :-
1) portal
2) News
3) informational
4) business/marketing
5) Blog
6) wiki
7) online social network
8) educational
9) entertainment
10) advocacy
11) web application
12) Content aggregation
13) Personal
the information given on a website must be accurate as no one avoids content of web page.
Multimedia refers to any application that combines text with graphics animation audio video and virtual reality.
A graphic is a digital representation of non text information and animation is the appearance of motion created by displaying a series of still images in sequence.
Audio includes music, speech, or any other sound.
streaming is the process of transferring data in a continuous and even flow.
video consist of images displayed in motion
Virtual reality is the use of computers to simulate a real or imagined situation that appears as three dimensional space.
A plug in is a program that extends the capability of a web browser.
web publishing is the development and maintenance of web pages.
what is e-commerce ?
it is a business transaction that occurs over an electronic network.
M-commerce identifies e-commerce that takes place using mobile devices.
E-mail is the transmission of messages and files via a computer network a email program allows you to create, send, receive, forward, store, print, and delete email messages.
A mailing list is a group of email addresses given a single name.
(IM) instant messaging is a real time internet communication service. A chat is real-time typed conversation that takes place on a computer. A chat room is a location of an internet server that permits users to chat with each other.
VoIP(voice over IP) enables users to speak to other users over the internet.
A newsgroup is an online area in which users have written discussions about a particular subject
A message board is a web based type of discussion group.
FTP( file protocol transfer) is an internet standard that permits file uploading and downloading with other computers on the internet. Many operating systems include FTP capabilities. An FTP server is a computer that allow user to download/upload files using FTP.
Netiquette is the code of acceptable internet behavior and you have to go by those rules.
Chapter 3: Software for systems
Application software consist of programs designed to make users more productive and assist with personal tasks.
it is available in a variety of forms such as Packaged software, custom software, web application, open source software, shareware, freeware, public domain software.
Business software is application software that assists people while performing business activities
There are many types of business software such as :-
Word processing :- allows users to create and manipulate documents
Spreadsheet software:- allows users to organize data in row and columns and perform calculations
charting depicts data in a spreadsheet in graphical form.
A database is a collection of data organized in a manner that allows access, retrieval and use of that data
-database software allows users to create, access, and manage a database
presentation software allows users to create visual aids for presentations to communicate ideas, messages and other information to a group
note taking software is application software that allows the user to enter typed text, handwritten comments drawings or sketches anywhere on a page
A software suite is a collection of individual programs available together as a unit
A personal information manager(PIM) is a application software that includes application calendar, address book, notepad.
Scaled versions of those software are available to work with smartphones and other mobile devices
Enterprises usually requires special computing solutions for various functional units
Some examples of graphic and multimedia software are :-
1) Computer aided design (CAD) software
2) Desktop publishing software
3) paint/image editing software
4) professional photo editing software (photoshop)
5)video and audio editing software
6) multimedia authoring software
Webpage authoring software helps users of all skill levels create web pages that include multimedia and interactive content.
Web Applications :- A web application is a website that allows users to access and interact with software from any computer or device that is connected to the internet
You can also learn tools for application software over online help it is the electronic equivalent of a user manual. you can ask questions or access the help topics in subject or alphabetical order.
web-based help provides updates and more comprehensive resource to respond to technical issues about software.
Web based training is a type of CBT that uses internet technology and consist of application software on the web
Distance learning(DL) is the delivery of education at one location while the learning takes place at other locations.
the inside of the system unit on a desktop personal computer includes: drive bay(s), power supply, sound card, video card, processor, memory.
The motherboard is the main circuit board of the system unit
- A computer chip contains integrated circuits.
Processor :- The processor also called the central processing unit(CPU), interprets and carries out the basic instructions that operate a computer
-Contain a control unit and an arithmetic logic unit (ALU)
The control unit is the component of the processor that directs and coordinates most of the operations in the computer
The arithmetic logic unit(ALU) performs arithmetic, comparison, and other operations.
for every instruction, a processor repeats a set of four basic operations, which comprise a machine cycle.
Fetch--->Decode---->excute-----> store.
A processor chip generates heat that could cause the chip to burn up so its requires additional cooling
-hear sinks
-liquid cooling technology
Parallel processing uses multiple processors simultaneously to execute a single program or task
- Massively parallel processing involves hundreds or thousands or processors.
Data Representation
analogue signals are continuous and vary in strength and quality
digital signals are in one of two states: on or off
most computers are digital
The binary system uses two unique digits(0 and 1) bits and bytes
Memory:- memory consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data.
memory stores in to three basic categories of items:
-the operating system
-other system software
-application programs
-Data being processed and the resulting information
each location in memory has an address
memory size is measured in KB, MB, GB, TB
The system unit contains two types of memory:
volatile meory :- loses its content when turned off eg:- RAM
non-volatile memory:- does not lose the content when turned off eg:- ROM, flash memory, and CMOS
Memory cache :- speeds the processes of the computer because it stores frequently used instructions and data
Access time is the amount of time it takes the processor to read from memory
-measured in nanoseconds.
Expansion slots and adapter cards :-
An expansion slot is a socket on the motherboard that can hold an adapter card
An adapter card enhances functions of a component of the system unit and/or provides connections to peripherals such as sound card or video card
With plug and play, the computer automatically can configure adapter cards and other peripherals as you install them.
removable flash memory includes
-memory cards,usb flash drives, and PC cards/express card.
Port and connectors :-
A port is the point at which a peripheral attaches to or communicate with a system unit and a connector joins a cable to a port.
A usb port can connect up to 127 different peripherals together with a single connector
* you can attach multiple peripherals using a single usb port with a usb hub.
A Bluetooth wireless port adapter converts a USB port into a Bluetooth port.
A smart phone communicate with a notebook computer using an lrDA port.
Port replicator :- it is an external device that provides connections to peripherals through ports built into the device
A docking station is an external device that attaches to a mobile computer or device.
Buses:- A bus allow the various devices both inside and attached to the system unit to communicate with each other
-data bus
-address bus
word size is the number of bits the processor can interpret and execute at a given time.
Expansion slots connect to expansion buses.
Bays:- A bay is an opening inside the system unit in which you can install additional equipment
Power supply :- it comverts the wall outlet AC power into DC power. some external peripherals have an AC adapter, which is an external power supply.
* clean your computer or mobile devices once or twice a year.
* turn off and unplug your computer or mobile device before cleaning it
* use compressed air to blow away dust
* use an antistatic wipe to clean the exterior of the case and a cleaning solution and soft cloth to clean the screen.
What is a output device ?
it is any type of hardware component that conveys information to one or more people
example of output devices :- monitor , printer ,speaker, headphones , data projectors interactive whiteboards etc.
Display devices :-
it visually conveys text, graphics and video information for eg :- monitor .
there are three type of display devices :-
1) liquid crystal display(LCD) - this uses liquid compound to present information on a display device
2) Active-matrix display- uses a grid of transistors and capacitors with the ability to hold charge for a certain period of time.
3) Passive-matrix display- uses a simple conductive grid to apply supply voltage to pixels on the display
LCD being the best out of those displays have features like high resolution , response time, brightness, dot pitch, contrast ratio.
Graphics processing unit controls the manipulation and display of graphics on a display device.LCD monitors use a digital signal and should plug into DVI port, HDMI port or display port.Plasma tv are display devices that use a gas plasma technology and offer screen size up to 150". HDTV is the most advanced form of digital televisions. A CRT monitor is a desktop monitor that contains a cathode ray tube..
Printers:-
printer gives out text or graphics content on a physical medium. non-impact printers form characters and graphics content on a piece of paper without actually striking it.
There are types of printer they are:-
1)Ink-jet printer- forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper
2) photo printers :- produces color photo lab quality/pictures by using ink-jet technology
3)laser printers :- high speed, high quality be it color or black&white
4) Thermal printers :- generates images by pushing electrically heated pins against the heat-sensetive paper eg:- thermal wax transfer printer, dye-sublimation printer.
5)Mobile printers :- small lightweight, batter powered printer that allows a mobile user to print from a n notebook computer, smartphone or other mobile device
6) label printers :- small printer that prints on adhesive-type material.
7)Postage printers :- Prints postage stamps.
8) plotters :- produce high-quality drawings
9)Large- format printers :- create photo-realistic quality color prints on a large scale.
- Multi-function peripheral (MFP) is a single device that prints, scans, copies and in some cases faxes
- Impact printers form characters and graphics on a piece of paper by striking a mechanism against an inked ribbon that physically contacts the paper
Dot-matrix printer - Produces printed images when tiny wire pins on a print head mechanism strike an inked ribbon
Line printer - Prints an entire line at a time
Speakers , Headphones & Earbuds
its an audio output device produces music speech or other sounds. users attach speakers to their computer to :-
*generate high quality sounds for playing games
*interact with multimedia presentation
*listen to music
*view movies
-headphones are speakers that cover or placed outside of ear.
- Earbuds rest inside ear canal.
- Some speakers are specifically designed to play audio from a portable media player. Eg: Wireless speakers.
- Voice output occurs when you hear a person's voice or when the computer talks to you through the speakers.
- Some website dedicate themselves to providing voice output.
- Voice output often works with voice input.
- VoIP uses voice output and voice input.
Data projector
- A device that takes the text and images displaying on a computer screen and projects them on a large screen
Interactive whiteoard
-A touch sensitive device resembling a dry-eras boards, that displays the image on a connected computer screen
Force-feedback Game Controller
- it sends resistance to the device in response to actions of the user
Tactile output
-it provides the user with a physical response from the device.
-Access time is amount of time taken a storage device to locate an item on a storage medium and time required to deliver an item from memory to the processor.
-A hard disk contains one or more inflexible, circular platters that use magnetic particles to store data, instructions and information. Hard disks can store data using longitudinal recording or perpendicular recording.
The features of a hard disk include: -
-Capacity
-Platters
-Cylinders
-Access Time
-Sectors and Tracks
-Read/write Heads
-Transfer rate
-Revolutions per minute
the hard disk arms move the read/write head,which reads items and writes item in the drive but location often is referred to by its cylinder. A head crash occurs when a read/write head touches the surface of a platter and always keep a backup of you hard disk.
-Formatting is the process of dividing the disk into tracks and sectors so that the operating system can store and locate data and information on the disk.
-RAID (redundant array of independent disks) is a group of two or more integrated hard disks
-An external hard disk is a separate free-standing hard disk that connects to your computer with cable or wireless.
-A removable hard disk is a hard disk that you insert and remove from a drive.
-A network attached storage (NAS) device is a server connected to a network with the sole purpose of providing storage.
Flash memory storage: -
-Flash memory chips are a type of solid-state media and contain no moving parts
-Solid state drives (SSDs) have several advantages over magnetic hard disks
1)Faster access time
2)Faster transfer rates
3)Last longer
4)Generate less heat and consume less power
-A memory card is a removable flash memory device that you insert and remove from aa slot in a computer.
-USB flash drives plug into a USB port on a computer or mobile device.
-Cloud storage is an internet service that provides storage to computer users.
-An optical disc have a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser.
-Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information where it read and writes data and information on a tape.
-A magnetic stripe card contains a magnetic stripe that stores information.
-A smart card stores data on a thin microprocessor embedded in the card.
there are many database software, they called database management system (DBMS) that will help managing a database it allows it users to do the following :-
1) create a computerized database
2) add , modify and delete data
3) sort and retrieve data
4) create forms and reports from the data
-the data integrity defines the quality of the data
- Garbage in and garbage out (GIGO) points out the accuracy of a computer's output depends on the accuracy of the input.
valuable and useful information is what every users need and it is very important for a company in its daily operation and long term decision and in their strategies such as :-
1) accurate :- valuable information needs to be accurate and free from error
2) timely - valuable information needs to be up to date
3) organized :- the information should be organized so its easy for the user to read
4) accessible :- the information should be accessible for all the users at any time.
5) useful :- the information should be useful in terms of its content.
6) cost effective :- the information needs to be cost effective that is getting high quality information at low price
The hierarchy of Data :-
each character is one byte
-Numbers, letters, space, punctuation marks, or other symbols
A field is a combination of one or more related characters like field name, field size, Data type
-File maintenance refers to the procedures that keep data current and up to date.
An example of file maintenance is adding records, modifying records, and deleting records.
-Adding record = add new records to a file when they obtain new data.
-Modifying records = users modify a record to correct inaccurate data or update old data.
-Deleting records = when a record no longer is needed, a user deletes it from a file
Validation compares data with a set of rules or values to find out if the data is correct
i) Alphabetic/Numeric check (ii)Range check (iii)Consistency check (iv)Completeness check (v)Check digit (vi)Other checks
File processing against databases :-
1) each database has its own set of files 1) programs and users share data
2) used for many years 2) reduce data redundancy
3) have data redundancy 3) improve data integrity
4) isolate data 4) share data
5) allow easier access
6) reduces development time
7) can be more vulnerable
Features in database management system:
1) Data dictionary- contains data about each file in the database and each field in those lines.
2) Query language- consist of simple, english-like statements that allow users to specify the data to display, print or store.
3) Query by example (QBE)- provide a graphical user interface to assist users with retrieving data.
4) Form- window on the screen that provide areas for entering or modifying data in a database.
5) Report generator- allows users to design a report on the screen, retrieve data into the report design and then display or print the report.
6) Security- only authorised users can access data at permitted times such as access privileges and principle of least privilege.
7) Backup and restore- to save the data in database in another storage medium and can be returned to its original form later.
8) Data model- consists of rules and standards that define how the database organises data.
For example:
Relational database- stores data in tables that consist rows and columns. Relationship is the link within the data.
Object oriented database (OODB)- stores data in objects. Examples of applications are multimedia database, groupware database, computer-aided design database and hypertext database.
Object relational database- create relationship between object oriented data.
Multidimensional database- can store data in more than two dimensions of data. A.k.a hypercube and it can consolidate data much faster than a relational database.
9) Data warehouse- huge database that stores and manages data required to analyse historical and current transactions.
Features of Web database:
*Shop for products or services- Amazon, Ebay, Alibaba
*Buy or sell stocks- NASDAQ, Suretrader.com.
*Search for a job- Jobstreet, Moster.com
*Make airline reservations- Air Asia, Malaysia Airline, Royal Brunei Airline.
*Register for college classes- UCSI Information Integrated System (IIS).
*Check semester grades- UCSI IIS, LMS.
Database Administration:-
The database design guidelines
Determine the purpose of the database.
Design the table or files.
Design the record and fields for each table or files.
Determine the relationships among the table and files.
Database analysts and administrators are responsible for managing and coordinating all the database activities.
Database analyst (DA)- decides on proper field placement, defines data relationships, and identifies users access privileges.
Database Administrator (DBA)- Creates and maintains the data dictionary, manages security, monitors performance, and checks backup and recovery procedures.
Information system is a collection of hardware, software, data, people and procedures that work together to produce quality information.
There are 5 phases in system development life cycle:-Planning-Analysis-Implementation-Maintenance
General guidelines for system development:-Group activities or task into phases.-Involve users.-Define standards.
Project management- process of planning, scheduling and controlling the activities during system development.
Analysis of project management:-Project scope.-Required activities.-Time estimates for each activities.-Cost estimates for each activities.-Order of activities.-Activities that can take place at the same time.
Feasibility- measure of how suitable the development of system will be to the organisation.
-Operational feasibility-Schedule feasibility -Technical feasibility -Economic feasibility
Documentation- the collection and summarisation of data and information.
How data and information gathered?-Review documentation.-Observe.-Survey.-Interview.-JAD (Joint Application Design) session.-Research.
The planning phase for a project begins when the steering committee receives a project request.
Four major activities are performed:
-Review and approve project requests.-Prioritize the project requests.-Allocate resources.-Form a project development team.
The analysis phase consists of two major activities:-Conduct a preliminary investigation-Perform detailed analysis
Process modeling (structured analysis and design) is an analysis and design technique that describes processes that transform inputs into outputs.-Entity-relationship diagrams-Data flow diagrams-Project dictionary
An entity-relationship diagram (ERD) is a tool that graphically shows the connections among entities in a system
Entities are objects in the system that have data.
A data flow diagram (DFD) is a tool that graphically shows the flow of data in a system.-Data flows-Processes-Data stores-Sources
The project dictionary contains all the documentation and deliverables of a project
Structured English is a style of writing that describes the steps in a process
The design phase consists of two major activities-Acquire hardware and software-Develop all of the details of the new or modified information system
The next step is to develop detailed design specificationsSometimes called a physical design-Database design-Input and output design-Program design
A prototype (proof of concept) is a working model of the proposed system
-Prototypes have inadequate or missing documentation-Users tend to embrace the prototype as a final system-Should not eliminate or replace activities
Computer-aided Software Engineering (CASE)- tools that are designed to support one or more activities of system development.
-Project repository.-Graphics.-Prototyping.-Quality assurance.-Code generator.-Housekeeping.
The purpose of the implementation phase is to construct the new or modified system and then deliver it.-Develop programs-Install and test the new system-Train users-Convert to the new system
Program Development Cycle-Analyze requirement-Design the solution-Validate the design-Implement the design-Test the solution-Document the solution
Maintenance
-Perform maintenance activities- to maintain the lifetime of the system.-Monitor system performance- to see if any improvement is needed. -Assess system security- manage the security and keep it updated.
Computer security plan should have:-Identify all information assets of an organisation.-Identify all security risks that may cause an information asset loss.-For each risk, identify the safeguards that exist to detect, prevent and recover from a loss.
1) portal
2) News
3) informational
4) business/marketing
5) Blog
6) wiki
7) online social network
8) educational
9) entertainment
10) advocacy
11) web application
12) Content aggregation
13) Personal
the information given on a website must be accurate as no one avoids content of web page.
Multimedia refers to any application that combines text with graphics animation audio video and virtual reality.
A graphic is a digital representation of non text information and animation is the appearance of motion created by displaying a series of still images in sequence.
Audio includes music, speech, or any other sound.
streaming is the process of transferring data in a continuous and even flow.
video consist of images displayed in motion
Virtual reality is the use of computers to simulate a real or imagined situation that appears as three dimensional space.
A plug in is a program that extends the capability of a web browser.
web publishing is the development and maintenance of web pages.
what is e-commerce ?
it is a business transaction that occurs over an electronic network.
M-commerce identifies e-commerce that takes place using mobile devices.
E-mail is the transmission of messages and files via a computer network a email program allows you to create, send, receive, forward, store, print, and delete email messages.
A mailing list is a group of email addresses given a single name.
(IM) instant messaging is a real time internet communication service. A chat is real-time typed conversation that takes place on a computer. A chat room is a location of an internet server that permits users to chat with each other.
VoIP(voice over IP) enables users to speak to other users over the internet.
A newsgroup is an online area in which users have written discussions about a particular subject
A message board is a web based type of discussion group.
FTP( file protocol transfer) is an internet standard that permits file uploading and downloading with other computers on the internet. Many operating systems include FTP capabilities. An FTP server is a computer that allow user to download/upload files using FTP.
Netiquette is the code of acceptable internet behavior and you have to go by those rules.
Chapter 3: Software for systems
Application software consist of programs designed to make users more productive and assist with personal tasks.
it is available in a variety of forms such as Packaged software, custom software, web application, open source software, shareware, freeware, public domain software.
Business software is application software that assists people while performing business activities
There are many types of business software such as :-
Word processing :- allows users to create and manipulate documents
Spreadsheet software:- allows users to organize data in row and columns and perform calculations
charting depicts data in a spreadsheet in graphical form.
A database is a collection of data organized in a manner that allows access, retrieval and use of that data
-database software allows users to create, access, and manage a database
presentation software allows users to create visual aids for presentations to communicate ideas, messages and other information to a group
note taking software is application software that allows the user to enter typed text, handwritten comments drawings or sketches anywhere on a page
A software suite is a collection of individual programs available together as a unit
A personal information manager(PIM) is a application software that includes application calendar, address book, notepad.
Scaled versions of those software are available to work with smartphones and other mobile devices
Enterprises usually requires special computing solutions for various functional units
Some examples of graphic and multimedia software are :-
1) Computer aided design (CAD) software
2) Desktop publishing software
3) paint/image editing software
4) professional photo editing software (photoshop)
5)video and audio editing software
6) multimedia authoring software
Webpage authoring software helps users of all skill levels create web pages that include multimedia and interactive content.
Web Applications :- A web application is a website that allows users to access and interact with software from any computer or device that is connected to the internet
You can also learn tools for application software over online help it is the electronic equivalent of a user manual. you can ask questions or access the help topics in subject or alphabetical order.
web-based help provides updates and more comprehensive resource to respond to technical issues about software.
Web based training is a type of CBT that uses internet technology and consist of application software on the web
Distance learning(DL) is the delivery of education at one location while the learning takes place at other locations.
Chapter 4 :- System unit components
The system unit is a case that contains electronic components of the computer used to process datathe inside of the system unit on a desktop personal computer includes: drive bay(s), power supply, sound card, video card, processor, memory.
The motherboard is the main circuit board of the system unit
- A computer chip contains integrated circuits.
Processor :- The processor also called the central processing unit(CPU), interprets and carries out the basic instructions that operate a computer
-Contain a control unit and an arithmetic logic unit (ALU)
The control unit is the component of the processor that directs and coordinates most of the operations in the computer
The arithmetic logic unit(ALU) performs arithmetic, comparison, and other operations.
for every instruction, a processor repeats a set of four basic operations, which comprise a machine cycle.
Fetch--->Decode---->excute-----> store.
A processor chip generates heat that could cause the chip to burn up so its requires additional cooling
-hear sinks
-liquid cooling technology
Parallel processing uses multiple processors simultaneously to execute a single program or task
- Massively parallel processing involves hundreds or thousands or processors.
Data Representation
analogue signals are continuous and vary in strength and quality
digital signals are in one of two states: on or off
most computers are digital
The binary system uses two unique digits(0 and 1) bits and bytes
Memory:- memory consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data.
memory stores in to three basic categories of items:
-the operating system
-other system software
-application programs
-Data being processed and the resulting information
each location in memory has an address
memory size is measured in KB, MB, GB, TB
The system unit contains two types of memory:
volatile meory :- loses its content when turned off eg:- RAM
non-volatile memory:- does not lose the content when turned off eg:- ROM, flash memory, and CMOS
Memory cache :- speeds the processes of the computer because it stores frequently used instructions and data
Access time is the amount of time it takes the processor to read from memory
-measured in nanoseconds.
Expansion slots and adapter cards :-
An expansion slot is a socket on the motherboard that can hold an adapter card
An adapter card enhances functions of a component of the system unit and/or provides connections to peripherals such as sound card or video card
With plug and play, the computer automatically can configure adapter cards and other peripherals as you install them.
removable flash memory includes
-memory cards,usb flash drives, and PC cards/express card.
Port and connectors :-
A port is the point at which a peripheral attaches to or communicate with a system unit and a connector joins a cable to a port.
A usb port can connect up to 127 different peripherals together with a single connector
* you can attach multiple peripherals using a single usb port with a usb hub.
A Bluetooth wireless port adapter converts a USB port into a Bluetooth port.
A smart phone communicate with a notebook computer using an lrDA port.
Port replicator :- it is an external device that provides connections to peripherals through ports built into the device
A docking station is an external device that attaches to a mobile computer or device.
Buses:- A bus allow the various devices both inside and attached to the system unit to communicate with each other
-data bus
-address bus
word size is the number of bits the processor can interpret and execute at a given time.
Expansion slots connect to expansion buses.
Bays:- A bay is an opening inside the system unit in which you can install additional equipment
Power supply :- it comverts the wall outlet AC power into DC power. some external peripherals have an AC adapter, which is an external power supply.
* clean your computer or mobile devices once or twice a year.
* turn off and unplug your computer or mobile device before cleaning it
* use compressed air to blow away dust
* use an antistatic wipe to clean the exterior of the case and a cleaning solution and soft cloth to clean the screen.
Chapter 5- utility programs and operating systems
system software have programs that controls or maintain the operation of the computer and its devices
operating system(OS) is a set of programs containing instructions that work together to coordinate all the acctivities among computer hardware resources
example of operating systems:-
*start and shut down a computer
*configure devices
*coordinate tasks
*Mange programs
*control a network
The process of starting and restarting is called booting where is divide into two which is cold boot and warm boot. A boot drive is the drive from which your computer starts where you can boot from a boot disk.
*A recovery disk contain a few system files that will start the computer.
*A user interface controls how you enter data and instruction and how information is displayed on the screen.
*Memory management optimizes the use of RAM and virtual memory is a portion of a storage medium functioning as additional RAM.
*A driver is a small program that tells the operating system how to communicate with a specific device
*plug and play automatically configures new device as you install the devices.
*automatic update automatically provides updates to the program.
*A stand alone operating system is a complete operating system that works on a desktop computer,notebook computer, or mobile computing device such as
*Windows 7- faster and more efficient
*Mac OS X- for easy to use
*UNIX- for multitasking
*Linux- for a open source popular and multitasking
*An embedded operating system resides on a ROM chip on a mobile device or consumer electronic devices
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*A utility program is a type of system software that allows a user to perform maintenance-type tasks.
*A file manager is a utility that performs functions related to file management where it displaying a list of files and organizing files in folders and more.
*A search utility is a program that attempts to locate a file on your computer based on criteria you specify.
*An image viewer allows user to display, copy, and print the contents of a graphics file.
*An uninstaller removes a program, as well as any associated entries in the system files.
*A disk derangement reorganizes the files and unused space on a computer's hard disk so that the operating system accesses data more quickly and programs run faster.
*A backup utility allows users to copy files to another storage medium.
*A restore utility reverses the process and returns backed up files to their original form.
*A media player allows you to view images and animation, listen to audio, and watch video files on your computer.
*Disc burning software writes text, graphics, audio and video files on a record able or re-writable optical disc.
*A personal computer maintenance utility identifies and fixes operating system problems and repairs disk problem.
Chapter-6-understanding input
Input is any data and instructions entered into the memory of a computer.
Instructions can be entered into a computer in the form of programs (a series of related instructions that tell computer what and how to perform task), commands (direct program) and user responses (an instruction a user issue to question displayed by program).
What is a Keyboard?
A keyboard is an input device that contains keys users press to enter data and instructions into a computer
Most desktop computer keyboards have between 101 and 105 keys
Most desktop computer keyboards have a numeric keypad on the right side of the keyboard
Most desktop computer keyboards have function keys, CTRL keys, ALT keys, and arrow keys
The insertion point, also known as the cursor, is a symbol on the screen that indicates where the next character you type will appear
An ergonomic keyboard has a design that reduces the chance of wrist and hand injuries
Ergonomics incorporates comfort, efficiency, and safety into the design of the workplace
Keyboards on mobile devices typically are smaller and/or have fewer keys
Some phones have predictive text input, which saves time when entering text using the phone’s keypad
What is a Pointing Device?
A pointing device is an input device that allows a user to control a pointer on the screen
A pointer is a small symbol on the screen whose location and shape change as a user moves a pointing device
A mouse is a pointing device that fits under the palm of your hand comfortably
A mouse can be wired or wireless
What is Voice Device?
Voice input is the process of entering input by speaking into a microphone
Voice recognition is the computer’s capability of distinguishing spoken words
Audio input is the process of entering any sound into the computer
Music production software allows users to record, compose, mix, and edit music and sounds
What is a video device ?
Video input is the process of capturing full-motion images and storing them on a computer’s storage medium
A Web cam is a type of digital video camera that enables a user to capture video and still images
A Web cam is a type of digital video camera that enables a user to send e-mail messages with video attachments
A Web cam is a type of digital video camera that enables a user to add live images to instant messages
A Web cam is a type of digital video camera that enables a user to broadcast live images over the Internet
A video conference is a meeting between two or more geographically separated people
Chapter-7:- Understanding output
Output :- it is the data that has been processed into the most useful form.What is a output device ?
it is any type of hardware component that conveys information to one or more people
example of output devices :- monitor , printer ,speaker, headphones , data projectors interactive whiteboards etc.
Display devices :-
it visually conveys text, graphics and video information for eg :- monitor .
there are three type of display devices :-
1) liquid crystal display(LCD) - this uses liquid compound to present information on a display device
2) Active-matrix display- uses a grid of transistors and capacitors with the ability to hold charge for a certain period of time.
3) Passive-matrix display- uses a simple conductive grid to apply supply voltage to pixels on the display
LCD being the best out of those displays have features like high resolution , response time, brightness, dot pitch, contrast ratio.
Graphics processing unit controls the manipulation and display of graphics on a display device.LCD monitors use a digital signal and should plug into DVI port, HDMI port or display port.Plasma tv are display devices that use a gas plasma technology and offer screen size up to 150". HDTV is the most advanced form of digital televisions. A CRT monitor is a desktop monitor that contains a cathode ray tube..
Printers:-
printer gives out text or graphics content on a physical medium. non-impact printers form characters and graphics content on a piece of paper without actually striking it.
There are types of printer they are:-
1)Ink-jet printer- forms characters and graphics by spraying tiny drops of liquid ink onto a piece of paper
2) photo printers :- produces color photo lab quality/pictures by using ink-jet technology
3)laser printers :- high speed, high quality be it color or black&white
4) Thermal printers :- generates images by pushing electrically heated pins against the heat-sensetive paper eg:- thermal wax transfer printer, dye-sublimation printer.
5)Mobile printers :- small lightweight, batter powered printer that allows a mobile user to print from a n notebook computer, smartphone or other mobile device
6) label printers :- small printer that prints on adhesive-type material.
7)Postage printers :- Prints postage stamps.
8) plotters :- produce high-quality drawings
9)Large- format printers :- create photo-realistic quality color prints on a large scale.
- Multi-function peripheral (MFP) is a single device that prints, scans, copies and in some cases faxes
- Impact printers form characters and graphics on a piece of paper by striking a mechanism against an inked ribbon that physically contacts the paper
Dot-matrix printer - Produces printed images when tiny wire pins on a print head mechanism strike an inked ribbon
Line printer - Prints an entire line at a time
Speakers , Headphones & Earbuds
its an audio output device produces music speech or other sounds. users attach speakers to their computer to :-
*generate high quality sounds for playing games
*interact with multimedia presentation
*listen to music
*view movies
-headphones are speakers that cover or placed outside of ear.
- Earbuds rest inside ear canal.
- Some speakers are specifically designed to play audio from a portable media player. Eg: Wireless speakers.
- Voice output occurs when you hear a person's voice or when the computer talks to you through the speakers.
- Some website dedicate themselves to providing voice output.
- Voice output often works with voice input.
- VoIP uses voice output and voice input.
Data projector
- A device that takes the text and images displaying on a computer screen and projects them on a large screen
Interactive whiteoard
-A touch sensitive device resembling a dry-eras boards, that displays the image on a connected computer screen
Force-feedback Game Controller
- it sends resistance to the device in response to actions of the user
Tactile output
-it provides the user with a physical response from the device.
Chapter 8 :- Types of storage
storage holds data, instructions and information for future use. A storage medium is the physical material on which a computer keeps data , instructions and information.
Storage device is the computer hardware that records and/or retrieves items ti and from storage media
. Reading is the process of transferring items from a storage medium into memory. Writing is the process of transferring items from memory to a storage medium.-Access time is amount of time taken a storage device to locate an item on a storage medium and time required to deliver an item from memory to the processor.
-A hard disk contains one or more inflexible, circular platters that use magnetic particles to store data, instructions and information. Hard disks can store data using longitudinal recording or perpendicular recording.
The features of a hard disk include: -
-Capacity
-Platters
-Cylinders
-Access Time
-Sectors and Tracks
-Read/write Heads
-Transfer rate
-Revolutions per minute
the hard disk arms move the read/write head,which reads items and writes item in the drive but location often is referred to by its cylinder. A head crash occurs when a read/write head touches the surface of a platter and always keep a backup of you hard disk.
-Formatting is the process of dividing the disk into tracks and sectors so that the operating system can store and locate data and information on the disk.
-RAID (redundant array of independent disks) is a group of two or more integrated hard disks
-An external hard disk is a separate free-standing hard disk that connects to your computer with cable or wireless.
-A removable hard disk is a hard disk that you insert and remove from a drive.
-A network attached storage (NAS) device is a server connected to a network with the sole purpose of providing storage.
Flash memory storage: -
-Flash memory chips are a type of solid-state media and contain no moving parts
-Solid state drives (SSDs) have several advantages over magnetic hard disks
1)Faster access time
2)Faster transfer rates
3)Last longer
4)Generate less heat and consume less power
-A memory card is a removable flash memory device that you insert and remove from aa slot in a computer.
-USB flash drives plug into a USB port on a computer or mobile device.
-Cloud storage is an internet service that provides storage to computer users.
-An optical disc have a flat, round, portable disc made of metal, plastic, and lacquer that is written and read by a laser.
-Tape is a magnetically coated ribbon of plastic capable of storing large amounts of data and information where it read and writes data and information on a tape.
-A magnetic stripe card contains a magnetic stripe that stores information.
-A smart card stores data on a thin microprocessor embedded in the card.
Chapter 10 :- Managing a database
database is a collection of data organised n a manner that allows access, retrieval and use of that data. collection of unprocessed data such as ext , image , numbers audio and video. information is where it processed data.there are many database software, they called database management system (DBMS) that will help managing a database it allows it users to do the following :-
1) create a computerized database
2) add , modify and delete data
3) sort and retrieve data
4) create forms and reports from the data
-the data integrity defines the quality of the data
- Garbage in and garbage out (GIGO) points out the accuracy of a computer's output depends on the accuracy of the input.
valuable and useful information is what every users need and it is very important for a company in its daily operation and long term decision and in their strategies such as :-
1) accurate :- valuable information needs to be accurate and free from error
2) timely - valuable information needs to be up to date
3) organized :- the information should be organized so its easy for the user to read
4) accessible :- the information should be accessible for all the users at any time.
5) useful :- the information should be useful in terms of its content.
6) cost effective :- the information needs to be cost effective that is getting high quality information at low price
The hierarchy of Data :-
each character is one byte
-Numbers, letters, space, punctuation marks, or other symbols
A field is a combination of one or more related characters like field name, field size, Data type
-File maintenance refers to the procedures that keep data current and up to date.
An example of file maintenance is adding records, modifying records, and deleting records.
-Adding record = add new records to a file when they obtain new data.
-Modifying records = users modify a record to correct inaccurate data or update old data.
-Deleting records = when a record no longer is needed, a user deletes it from a file
Validation compares data with a set of rules or values to find out if the data is correct
i) Alphabetic/Numeric check (ii)Range check (iii)Consistency check (iv)Completeness check (v)Check digit (vi)Other checks
File processing against databases :-
1) each database has its own set of files 1) programs and users share data
2) used for many years 2) reduce data redundancy
3) have data redundancy 3) improve data integrity
4) isolate data 4) share data
5) allow easier access
6) reduces development time
7) can be more vulnerable
Features in database management system:
1) Data dictionary- contains data about each file in the database and each field in those lines.
2) Query language- consist of simple, english-like statements that allow users to specify the data to display, print or store.
3) Query by example (QBE)- provide a graphical user interface to assist users with retrieving data.
4) Form- window on the screen that provide areas for entering or modifying data in a database.
5) Report generator- allows users to design a report on the screen, retrieve data into the report design and then display or print the report.
6) Security- only authorised users can access data at permitted times such as access privileges and principle of least privilege.
7) Backup and restore- to save the data in database in another storage medium and can be returned to its original form later.
8) Data model- consists of rules and standards that define how the database organises data.
For example:
Relational database- stores data in tables that consist rows and columns. Relationship is the link within the data.
Object oriented database (OODB)- stores data in objects. Examples of applications are multimedia database, groupware database, computer-aided design database and hypertext database.
Object relational database- create relationship between object oriented data.
Multidimensional database- can store data in more than two dimensions of data. A.k.a hypercube and it can consolidate data much faster than a relational database.
9) Data warehouse- huge database that stores and manages data required to analyse historical and current transactions.
Features of Web database:
*Shop for products or services- Amazon, Ebay, Alibaba
*Buy or sell stocks- NASDAQ, Suretrader.com.
*Search for a job- Jobstreet, Moster.com
*Make airline reservations- Air Asia, Malaysia Airline, Royal Brunei Airline.
*Register for college classes- UCSI Information Integrated System (IIS).
*Check semester grades- UCSI IIS, LMS.
Database Administration:-
The database design guidelines
Determine the purpose of the database.
Design the table or files.
Design the record and fields for each table or files.
Determine the relationships among the table and files.
Database analysts and administrators are responsible for managing and coordinating all the database activities.
Database analyst (DA)- decides on proper field placement, defines data relationships, and identifies users access privileges.
Database Administrator (DBA)- Creates and maintains the data dictionary, manages security, monitors performance, and checks backup and recovery procedures.
Chapter-11 :- Manage computing securely, safely and ethically
A computer security risk is any event or action that could cause a loss or damage to computer hardware, software, data or even important information.
A cyber crime is an online or internet based illegal act such as hackers, crackers, script kiddies, corporate spies and more.
Hackers :- are person who uses computer to gain unauthorized access to data and personal information.
Crackers also known as black hat hacker is an individual with extensive computer knowledge whose purpose is to breach or bypass internet security or gain access to software without paying royalties. the general view is that, while hackers build things, crackers break things.
Script Kiddies are person who uses existing computer scripts or codes to hack into computers, lacking the expertise to write their own.
-An online security service is a web site that evaluates your computer to check for internet and e-mail vulnerabilities.
Type of internet and network attacks:-
Computer virus- Affects a computer negatively by altering the way the computer works.
Worm- Copies itself repeatedly using up resource and completely shut down the computer and network.
Trojan Horse- A malicious program that hides within or looks like a legitimate program.
Rootkit- A set of software tools that enable an unauthorized user to gain control of a computer system without being detected.
-An infected computer has one or more of the following symptoms; -
Operating system runs much slower than usual.
Available memory is less than expected.
Files become corrupted.
system properties change.
Music or unusual sound plays randomly.
Operating system shuts down unexpectedly.
Programs or files do not work properly.
Operating system does not start up.
-A botnet is a group of compromised computers connected to a network. A compromised computer is know as a zombie.
-A denial of service attacks (Dos attack) disrupts computer access to internet services.
-A back door is a program or set of instructions in a program that allow users to bypass security controls.
-Spoofing is a technique intruders use to make their network or internet transmission appear legitimate.
-A firewall is hardware and/or software that protects a network's resources from intrusion.
-Intrusion detection software:-
*Analyzes all network traffic
*Assesses system vulnerabilities
*Identifies any unauthorized intrusions
*Notifies network administrators of suspicious behavior patterns or system breaches.
-Honeypot:-
*Vulnerable computer that is set up to entice an intruder to break into it.
Unauthorized Access and Use:-
-Unauthorized access is the use of a computer or network without permission
-Unauthorized use is the use of a computer or its data for unapproved or possibly illegal activities.
-Organizations take several measure to help prevent unauthorized access and use
*Acceptable use policy
*Disable file and printer sharing
*Firewalls
*Intrusion detection software
-Access controls define who can access a computer, when they can access it and what actions they can take
*Two-phase processes called identification and authentication
*User name
*Password
*Passphrase
*CAPTCHA
-A bio-metric device authenticates a person’s identity by translating a personal characteristic into a digital code that is compared with a digital code in a computer
-Digital forensics is the discovery , collection, and analysis of evidence found on computer and network. many areas use digital forensics such as
*Law enforcement
*Criminal prosecutors
*Military intelligence
*Insurance agencies
*Information security departments
Hardware Theft and Vandalism: -
-Hardware theft is the act of stealing computer equipment
-Hardware vandalism is the act of defacing or destroying computer equipment.
To help reduce the of change of theft, companies and schools use a variety of security measures
*Physical access controls
*Alarm system
*Cables to lock equipment
*Real time location system
*Password, possessed objects, and bio-metrics
-Software theft occurs when someone; -
*Steals software media.
*Intentionally erases programs.
*illegally copies a program.
*illegally registers and/or activates a program.
Software Theft: -
-A single-user license agreement typically contains the following conditions
permitted to
*install the software on one computer
*Make one copy of the software
*Remove the software from your computer before giving it away or selling it
Not permitted to
*install the software on a network
*Give copies to friends or colleagues while continuing to use the software
*Export the software
*Rent or lease the software
Copying, loaning, borrowing, renting, or distributing software can be a violation of copyright law where some software requires product activation to function fully.
-Information theft occurs when someone steals personal or confidential information .
-Encryption is a process of converting readable data into unreadable characters to prevent unauthorized access.
-A digital signature is an encrypted code that a person, website, or organization attaches to an electronic message to verify the identity of the sender.
popular security techniques include:-
*Digital certificates
*Transport layer security (TLS)
*Secure HTTP
*VPN
-A system failure is the prolonged malfunction of a computer. A variety of factors can lead to system failure including:-
*Aging hardware
*Natural disasters
*Electrical power problems such as noise, under-voltages and over-voltages
*Errors in computer programs
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Two ways to protect from system failures caused by electrical power variations include surge protectors and uninterruptible power supplies (UPS).
-A backup is a duplicate of a file, program, or disk that can be used if the original is lost, damaged. or destroyed. To back up a file means to make a copy of it. Offsite backups are stored in a location separate form the computer site such as cloud storage.
Ethics and Society:-
The bets way to prevent security risk is to have ethics and society.
-Computer ethics are the moral guidelines that govern the use of computer and information systems.
-Intellectual property rights are the rights to which creators are entitled for their work. A copyright protects any tangible form of expression.
-IT code of conduct is a written guideline that helps determine whether a specific computer action is ethical or unethical. The IT code of conduct:-
*Computers may not be used to harm other people.
*Employees may not interfere with others computer work.
*Employees may not meddle in others computer files.
*Computers may not be used to steal.
*Computers may not be used to bear false witness.
*Employees may not copy or use software illegally.
*Employees may not use others computer resource without authorization.
*Employees may not use others intellectual property as their own.
*Employees shall consider the social impact of programs and system they design.
*Employees always should use computers in a way that demonstrates consideration and respect for fellow humans.
Green computing :- it involves reducing the electricity and environmental waste while using a computer
* use computers and devices that comply with the energy star program
*do not leave the computer running overnight
*turn off the monitor, printer and other devices when not in use
*use lcd monitors instead of crt moitors.
*use paperless methods to communicate.
* recycle paper.
* buy recycled paper.
* recycle toner cartridges
* recycle old computers, printers and other devices.
* telecommute to save gas
* use video conferencing and VoIP for meetings.
-Information privacy refers to the right of individuals and companies to deny or restrict the collection and use of information about them where huge database store data online and it is important to safeguard your information.
-Information privacy refers to the right of individuals and companies to deny or restrict the collection and use of information about them where huge database store data online and it is important to safeguard your information.
Examples on how to safeguard personal information;-
1) Fill only necessary information on any form.
2) Avoid shopping club and buyer cards.
3) Ask before giving personal information to any merchants.
4) Install a cookie manager to filter cookies.
5) Turn off file and printer sharing on internet connection.
6) Install a personal firewall.
7) Inform merchant not to distribute your personal information.
8) Clear history file frequently on browser.
9) Do not reply to spam for any reason.
10) Surf the web anonymously.
-A cookie is a small text file that a web server stores on your computer such as:-
*Allow for personalization
*Store users password
*Assist with online shopping
*Track how often users visit a site
*Target advertisements
-Spam is an unsolicited e-mail message or newsgroup posting.
-E-mail filtering blocks e-mail messages from designated sources.
-Anti-spam programs attempt to remove spam before it reaches to your inbox.
-Phishing is a scam in which a perpetrator sends an official looking e-mail message that attempts to obtain your personal and financial information.
-Pharming is a scam where a perpetrator attempts to obtain your personal and financial information via spoofing.
-Content filtering is the process of restricting access to certain material on the web.
-Web filtering software restricts access to specified websites.
-Social engineering is defined as gaining unauthorized access or obtaining confidential information by taking advantage of trust and naivety.
-Employee monitoring involves the use of computers to observe, record and review an employee's use of a computer.
Chapter 12:- EXPLORING INFORMATION SYSTEM DEVELOPMENT
System development is the development of an information system. System is a set of components that interact to achieve a common goal. System development should involve representatives from each department in which the proposed system will be used.
Information system is a collection of hardware, software, data, people and procedures that work together to produce quality information.
There are 5 phases in system development life cycle:-Planning-Analysis-Implementation-Maintenance
General guidelines for system development:-Group activities or task into phases.-Involve users.-Define standards.
Project management- process of planning, scheduling and controlling the activities during system development.
Analysis of project management:-Project scope.-Required activities.-Time estimates for each activities.-Cost estimates for each activities.-Order of activities.-Activities that can take place at the same time.
Feasibility- measure of how suitable the development of system will be to the organisation.
-Operational feasibility-Schedule feasibility -Technical feasibility -Economic feasibility
Documentation- the collection and summarisation of data and information.
How data and information gathered?-Review documentation.-Observe.-Survey.-Interview.-JAD (Joint Application Design) session.-Research.
The planning phase for a project begins when the steering committee receives a project request.
Four major activities are performed:
-Review and approve project requests.-Prioritize the project requests.-Allocate resources.-Form a project development team.
The analysis phase consists of two major activities:-Conduct a preliminary investigation-Perform detailed analysis
Process modeling (structured analysis and design) is an analysis and design technique that describes processes that transform inputs into outputs.-Entity-relationship diagrams-Data flow diagrams-Project dictionary
An entity-relationship diagram (ERD) is a tool that graphically shows the connections among entities in a system
Entities are objects in the system that have data.
A data flow diagram (DFD) is a tool that graphically shows the flow of data in a system.-Data flows-Processes-Data stores-Sources
The project dictionary contains all the documentation and deliverables of a project
Structured English is a style of writing that describes the steps in a process
The design phase consists of two major activities-Acquire hardware and software-Develop all of the details of the new or modified information system
The next step is to develop detailed design specificationsSometimes called a physical design-Database design-Input and output design-Program design
A prototype (proof of concept) is a working model of the proposed system
-Prototypes have inadequate or missing documentation-Users tend to embrace the prototype as a final system-Should not eliminate or replace activities
Computer-aided Software Engineering (CASE)- tools that are designed to support one or more activities of system development.
-Project repository.-Graphics.-Prototyping.-Quality assurance.-Code generator.-Housekeeping.
The purpose of the implementation phase is to construct the new or modified system and then deliver it.-Develop programs-Install and test the new system-Train users-Convert to the new system
Program Development Cycle-Analyze requirement-Design the solution-Validate the design-Implement the design-Test the solution-Document the solution
Maintenance
-Perform maintenance activities- to maintain the lifetime of the system.-Monitor system performance- to see if any improvement is needed. -Assess system security- manage the security and keep it updated.
Computer security plan should have:-Identify all information assets of an organisation.-Identify all security risks that may cause an information asset loss.-For each risk, identify the safeguards that exist to detect, prevent and recover from a loss.
Chapter 13:- Computer programs and programming language
A programming language is the language that programmers use to develop software programs, scripts, or other sets of instructions for computers to execute.Example application : C++ , JAVA .Computer program is a series of instructions that directs a computer to perform tasks. Created by a programmer using a programming language.
Low-level Language:
-Machine language is the first generation of programming languages, this language is only recognized by the computer.
-Assembly language is the second generation of programming languages. use of symbolic instructions.
Source program contains the code to be converted to machine language.
Procedural language instructions that tell the computer what and how to do.
-Procedural Languages
In a procedural language, the programmer writes instructions that tell the computer what to accomplish and how to do it.
-Third-generation language (3GL)
A compiler translates an entire program before executing it.
An interpreter converts and executes one code statement at a time.
The C programming language is used to write many of today’s programs.
-COBOL (COmmon Business-Oriented Language) is designed for business applications, but easy to read because of the English-like statements.
-Object-Oriented Programming Languages and Program Development Tools
An object-oriented programming (OOP) language allows programmers the ability to reuse and modify existing objects.
Other advantages include:
objects can be reused
programmers create applications faster
work well in a RAD environment
most program development tools are IDEs
-Java is an object-oriented programming language developed by Sun Microsystems.
The Just-in-time (JIT) compiler converts the bytecode into machine-dependent code.
The Microsoft .NET Framework allows almost any type of program to run on the Internet or an internal business network, as well as computers and mobile devices.
Features include:
-CLR (Common Language Runtime)
-Classes
-C++ is an extension of the C programming language.
-C# is based on C++ and was developed by Microsoft.
-F# combines the benefits of an object-oriented language with those of a functional language.
-Visual Studio is Microsoft’s suite of program development tools:
1)Visual Basic is based on the BASIC programming language
2)Visual C++ is based on C++
3)Visual C# combines the programming elements of C++ with an easier, rapid-development environment]
A visual programming language is a language that uses a visual or graphical interface for creating all source code.
Borland’s Delphi is a powerful program development tool that is ideal for building large-scale enterprise and Web applications in a RAD environment.
PowerBuilder is a powerful program development RAD tool.
it is the best for Web-based, .NET, and large-scale enterprise object-oriented applications.
Other Programming Languages and Development Tools
A 4GL (fourth-generation language) is a nonprocedural language that enables users and programmers to access data in a database.
One popular 4GL is SQL
Classic programming languages include:
*Ada
*ALGOL
*APL
*BASIC
*Forth
*FORTRAN
*HperTalk
*LISP
*Logo
*Modula-2
*Pascal
*PILOT
*PL/1
*Prolog
*RPG
*Smalltalk
An application generator is a program that creates source code or machine code from a specification of the required functionality.
Often bundled as part of a DBMS
A macro is a series of statements that instructs an application how to complete a task.
You usually create the macro in one of two ways:
Record the macro with a macro recorder
Write the macro
Web Page Development
HTML is a special formatting language that programmers use to format documents for display on the Web.
XHTML is a markup language that allows Web sites to be displayed more easily on mobile devices.
XML allows Web developers to create customized tags and use predefined tags to display content appropriately on various devices.-WML is a subset of XML and is used to design pages for microbrowsers.
Two applications of XML are RSS 2.0 and ATOM.
Web browsers can execute short programs to add interactive elements to Web pages.
To send and receive information between your computer and a Web server, these programs use the CGI (common gateway interface).
Programmers write scripts, applets, servlets, or ActiveX controls using a variety of languages:
*JavaScript
*Perl
*PHP
*Rexx
*Tcl
*VBScript
Dynamic HTML (DHTML) allows Web developers to include more graphical interest and interactivity.
Cascading style sheets (CSS) contain the formats for how a particular object should be displayed.
Ruby on Rails (RoR) provides technologies for developing object-oriented, database-driven Web sites.
Web 2.0 allows Web sites to provide a means for users to:
*Share personal information
*Allow users to modify Web site content
*Have application software built into the site
Most Web 2.0 sites use APIs
-An API enables programmers to interact with an environment such as a Web site or operating system.
Web page authoring software can create sophisticated Web pages that include images, video, audio, animation, and other effects
*Dreamweaver
*Expression Web
*Flash
*SharePoint Designer
Multimedia Program Development
Multimedia authoring software allows programmers to combine text, graphics, animation, audio, and video in an interactive presentation.
*ToolBook
*Director
Program development consists of a series of steps programmers use to build computer programs.
- Analyze Requirements
To initiate program development, programmer:
*Reviews the requirements
*Meets with the systems analyst and users
*Identifies input, processing, and output
*IPO chart
– Design Solution
Design a solution algorithm.
In structured design, the programmer typically begins with a general design and moves toward a more detailed design.
Programmers use a hierarchy chart to show program modules graphically.
With object-oriented (OO) design, the programmer packages the data and the program into a single object
-Encapsulation
The sequence control structure shows one or more actions following each other in order.
The selection control structure tells the program which action to take, based on a certain condition.
-If then else
-case
The repetition control structure enables a program to perform one or more actions repeatedly as long as a certain condition is met.
A program flowchart graphically shows the logic in a solution algorithm.
Flowcharting software makes it easy to modify and update flowcharts
-SmartDraw
-Visio
Pseudocode uses a condensed form of English to convey program logic.
UML (Unified Modeling Language) has been adopted as a standard notation for object modeling and development.
– Validate Design
Check for logic errors using test data
-Develop various sets of test data
-Determine the expected result
-Step through the algorithm
-Compare the results
-Repeat steps for each set of test data
– Implement Design
Implementation of the design includes using a program development tool that assists the programmer by:
-Generating or providing some or all code
-Writing the code that translates the design into a computer program
-Creating the user interface
Extreme programming is a strategy where programmers immediately begin coding and testing solutions as soon as requirements are defined.
– Test Solution
The goal of program testing is to ensure the program runs correctly and is error free.
-Errors include syntax errors and logic errors.
-Debugging the program involves removing the bugs.
-A beta is a program that has most or all of its features and functionality implemented.
– Document Solution
In documenting the solution, the programmer performs two activities:
-Review the program code
-Review all the documentation
Chapter 14:- Enterprise software
Enterprise computing is a buzzword that refers to business-oriented information technology that is critical to a company's operations. It involves the use of computers in networks such as LANs and WANs (Wide Area Network), or a series of interconnected networks that encompasses a variety od different operating systems, protocols and network architectures.
Types of enterprises:-
1) Retail
2) Manufacturing
3) Service
4) Wholesale
5) Government
6) Educational
7) Transportation
The common categories in an enterprise are:-
1) Executive management.
2) Middle management.
3) Operational management.
4) Non-management employess.
-Enterprise information is the information gathered in the ongoing operations of an enterprise-sized organization. For example, Business intelligence, Business process management, and Business process automation. Resources will be managed by managers by Planning, Organising, Leading, and Controlling.
-The information system is a set of hardware, software, data, people and procedures that work together to produce information.
Functional units within an enterprise:-
Accounting and Finance
1)-Accounting software manages the everyday transaction.
2)-Billing software helps the company reconcile purchases with customer payments.
3)-The financial software helps managers budget, forecast, and analyze.
Human Resources
1)-Human resources information system (HRIS) manages one or more human resources functions.
2)-Employee relationship management systems manage communication between employees and the business.
Engineering or Product Development
1)-Computer-aided design (CAD) uses a computer and special software to aid in engineering, drafting, and design.
2)-Computer-aided engineering (CAE) uses computers to test product designs
Manufacturing
1)-Computer-aided manufacturing (CAM) is the use of computers to control production equipment.
2)-Computer-integrated manufacturing (CIM) uses the computer to integrated the many different operations of the manufacturing process.
3)-Material Requirements Planning (MRP) uses software to help monitor and control processes related to production.
4)-Manufacturing Resource Planning II (MRP II) is an extension of MRP and also includes software helps in scheduling
5)-Quality control system helps an organization maintain or improve the quality of its products or services.
Marketing
-Marketing information system serves as a central repository for the tasks of a marketing department.
Sales
-Sales force automation (SFA) software equips traveling salespeople with the electronic tools they need to be more productive.
Distribution
-Distribution system provide forecasting for inventory control, manage and track shipping of products and provide information and analysis on inventory in a warehouse.
Customer service
-Customer interaction management (CIM) software manages the day-to-day interactions with customers.
Information Technology
1)-Makes technology decisions for the enterprise in the case like whether to build or buy new information system and when a computer or information system has outlived its useful life.
2)-Web Site Management Programs- collect data designed to help organizations make informed decisions regarding their Web presence.
3)-Office Information System (OIS)- oriented to word processing, electronic mail, and other similar office functions.
4)-Transaction Processing System (TPS)- for business transactions involving the collection, modification, and retrieval of all transaction data.
5)-Management Information System (MIS)- focuses on management of information systems to provide efficiency and effectiveness of strategic decision making.
6)-Decision Support System (DSS)- a set of related computer programs and data required to assists with analysis and decision making within an organization.
7)-Expert System- a piece of software programmed using artificial intelligence. It uses the database of expert knowledge to offer advice or make the decision. For example, it is the help button found in our operating system.
8)-Integrated Information System (IIS)- an array of multiple information sets linked together in an organized way. This contains three processes:-
-Customer relationship management manages information about customers, interactions with customers, past purchases, and interests.
-Enterprise resource planning provides centralized, integrated software to help manage and coordinate ongoing activities.
-Content management systems are information systems that combine database, software, and procedures.
Enterprise-wide Technologies and Methodologies:-
-Portal is a collection of links, content, and services presented on a web page that is interesting for a particular job function.
-Data warehouse is a huge database that stores and manages the data required to analyze historical and current transactions.
-EDI (Electronic Data Interchange) is set of standards that control the transfer of business data and information among computers both within and among enterprises.
-Extranet is the portion of a company's network that allows customers or suppliers of a company to access parts of an enterprise's intranet.
-Web Services allows business to create products and B2B interactions over the internet.
-Document management system (DMS) allows for storage and management of a company's documents.
-Workflow is a defined the process that identifies the specific set of steps involved in completing a particular project or business process.
-Virtual Private Network allows customers or vendors to connect to company network server in a private network connection.
-Virtualization is the practice of sharing or pooling computing resources.
1) Server virtualisation - physical server can be divided into many virtual servers.
2) Storage virtualisation - single logical storage device can be created from many physical storage devices
-Cloud computing is an internet service that provides computing needs to computer users.
1) Grid computing combines many servers and/or personal computers on a network to act as one large computer.
Types of E-commerce:
1) E-retail- occurs when retailers use the Web to sell their products or services.
2) Finance- financial tools such as online banking and online trading services are provided.
3) Travel- travel related services like airline reservations, destinations are provided.
4) Entertainment and Media- entertainment and media such as video, audio or games are provided.
5) Health- health related services or information are provided.
-Enterprise hardware allows large organizations to manage and store information and data using devices geared for:-
*Heavy use
*Maximum availability
*Maximum efficiency
-RAID duplicates data and implements duplication in different ways.
-Network attached storage (NAS) is a server that provides storage to users and information systems attached to the network.
-Storage area network (SAN) is a high-speed network that provides storage to other servers to which it is attached.
-Enterprise storage system is a strategy that focuses on the availability, protection, organization, and backup of storage in a company.
-Blade server packs a complete computer server on a single card (called a blade) rather than a system unit. The individual blades insert in a blade server chassis.
-Thin client is a small terminal like computer that mostly relies on a server for data storage and processing is usually done on a server.
-High-availability system continues running and performing tasks for at least 99 percent of the time
-Scalability is a measure of how well computer hardware, software, or an information system can grow to meet increasing performance demands.
-Interoperability Cthe ability of an information system to share information with other information systems within an enterprise.
-Disaster recovery plan is a written plan describing the steps a company would take to restore computer operations in the event of a disaster. contains four major components:-
*Emergency plan
*Backup plan
*Recovery plan
*Test plan
Chapter 15:- Its finally over!!!
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