Notes of Information And Communication Technology

What is information technology?

Information technology is combination of two technologies Computer Technology and Telecommunication technology. Where computer technology storing information, protecting information, processing the information and on the other hand telecommunication technology related with transmitting the information.

There are following major components of IT.

1.    Computer science

2.    Telecommunication engineering

3.    Computer engineering

Computer science (or computing science): -

Computer Science some time also called computing science deals with study of computer software and software system this includes their theory, design, development, and application.

Telecommunications: -

Telecommunication related with transmitting the signals and electromagnetic waves over a distance for the purpose of communication. Telecommunications is a pluer form because it is collection of many different technologies such as s telegraph, telephone, and teleprompter, networks, radio, microwave transmission, fiber optics, and communications satellites.

Computer engineering: -

It’s related with designing and development of hardware and system software.

Above components are divided in to following subcomponents.

·         Databases

·         Front end Applications

·         Network

Database: -

Database is related with storing the data on a single pace which is shareable by more than one user at same time.

Front end Applications: -

Front-end applications are software which is used by the end user for the purpose of entering and retrieving (displaying) the data on screen.

Network: -

Networking is another component of Information Technology. Networking technology consists of both software and hardware. The term network is defined as the interconnection of several different computers by communication media.

Operating Systems: -

An operating system is a collection of system program that controls the overall operation of a computer system. Operating system is the most basic program within the computer system it’s provide the interface that user easily control and use the computer machines.

What is DATA?

 Data is a collection of facts, such as numbers, words, measurements, observations or even just descriptions of things. Anything in the raw form means that not meaningful from is called data. Computer data may be processed by the computer and  stored in files and folders on the computer. The data that stored in computer is always in binary form.

Types of data:

1. Alphabetic data

2. Numeric data

3. Alphanumeric data

For example the score of the student in exam or the number of visitors to a website by country is an example of data

What is Information?

Information is organized or classified from of data which has some meaningful values for the receiver. Information must have some characteristics such that Information should be available when required, Information should be accurate and Information should be complete.

For example the average score of a class or of the entire school is information that can be derived from the given data.

Another example is id we have data from web site that how many visitor or visit the site the finding out the traffic from Pakistan is information.

Electronic data processing (EDP)

 The procedure of transferring the raw data in to information by processing with the help computer and its programs in an environment involving electronic communication is called Electronic data processing (EDP). The information and communication technology have great impact on EDP as compare to processing done by manual system. For example: stock updates applied to an inventory, banking transactions applied to account and customer master files, booking and ticketing transactions to an airline's reservation system, billing for utility services.

There are three basic steps involve in EDP.

 1. Capturing the input data 2. Manipulating the data 3. Managing the data

These function are done very easily and quickly with the help of Information and communication technology.

Capturing The Input Data:

The input is primly step for EDP. The data can be captured directly in the paperless machine-readable form rather then its store first in manual form. For example you can get the user input directly form on line form. User use his ATM or Credit Card , thumbs expression system, capturing the price with bar cod reader.

Manipulating the data

Data manipulation is the process of taking data and manipulating it in a method to be easier read or organized. For example Arranging the data, Arithmetic manipulation in which calculation are involve. This will be easily done by the help of IT. There are many query languages which provide very enhance manipulation system. Word processor also one the example of manipulation in EDP.

Managing the output result

When data is gathering and when it’s manipulated according to the desire output. The data is ready to present. The output is display on the screen and data is saved on the file, which can be printed on a print attached to get the hard copy of it.

What are the basic
element of electronic data processing?

There are four basic element of EDP system.

1.    Hardware

2.    Software

3.    Procedure

4.    Personnel

1) Hardware:

The physical component of computer such as all electronic and mechanical components is called hardware. Even an electronic wire is also includes in hardware. e.g keyboard, CPU, and monitor.

2) Software:

The term software refers to the   computer program. There are two type of software which are application software, design for specific purpose and other are system software.


3) Procedure:

Procedure is a set of preplanned steps, polices which the computer system adopt in order to perform in specific task or in order to turn data into information.

4) Personnel: 

The individual who work in an environment basically related to computer are known as computer personnel. They belonged to different type according to their nature of work and educational background. There are

·         System administrator

·         System analysis

·         Programmer

·         Operator

·         User

System administrator: - S/he supervises the overall management of system and maintains the hardware/software.

System analysis: - S/he is knowledgeable in the programming area but have broader responsibilities/he plan and designs not just individual program but the whole system according to the need of customer and collets all the relative information.

Programmer: - A programmer designs writes, test and implements a program to a particular language/packages in the light of the information provided by the system analyst.

Operator: - Operator is a commonly known as a key Punch operator (Kpo) who is required to input the relevant data into the program devolved by the programmer or to prepare data on cards, disk and tape.


They are the people to whom computer system are supposed to serve. They can be researchers, executive, engineers, and government planners.

Difference between conventional or manual data processing?

The conventional or manual data processing is the manual method of transforming data into information, all the work is done by human being i.e. collection and classifying of data. Perfuming manual calculation and hence producing the desire output /result. The method of data processing is useful in organization where the process is limited. But when the volume of data is increase then we need electronic data processing. The example of this type of processing is the manual system adopted by majority of government offices, school, and collage and private sector.

Difference b/w manual and electronic data processing




It is inexpensive

it is more expansive.

Complex problem solving takes

it take less time in complex situation To much time

Data processed by human

Data processed my machine

Take more human effort

Required less effort

Results are not accurate all the time

result are accurate always

Processing speed is very slow

processing speed is blindly fats.

Input Devices

The entire computer peripheral which is used to provide data for the processing are called input devices. Most common examples of input devices are keyboard mouse.


A keyboard is an input device which is used to enter the data. Keyboard consists on different button and each button can be used to input a character to a computer or call for some specific function. A keyboard typically contains keys for individual letters, numbers and special characters, as well as keys for specific functions. A keyboard is connected to a computer system using a cable or a wireless connection.

Mouse: -

A mouse is a pointing device which controls a tilt arrow which is calls pointer on the screen. A standard mouse has two buttons. Each button can be used as input instruction to computer.

Now days the mouse is an integral part of the graphical user interface (GUI) of any personal computer.

Scanner: -

Scanner is an input device which captures the data form hard copy such as photo, document, poster and then transfer in digital image which can be edited and store in the computer. Some time scanner used special software which helps us to scan the images. There are some other types of scanner for example barcode reader also read the barcode data by scanning the barcode.



Microphones some time called mice accept the audio input. Microphone conneteted with sound card of the system and then get our sound. The sound card then translate analog sound signal from the microphone into digital codes the computer can store and process.

Compact Disk: -

Compact disk some time also called CD is also used to input the information in computer. A special device which read the data form CD called CD RoM is used for this purpose.

Optical Mark Reader OMR

This device capable of detecting data in the form of marks of pen or pencil. For example, this device is used to check the objective test sheets filled by the students in pencil. The test forms are fed into an optical mark-sensing device that converts the presence of pencil marks into electrical signals that can be input to a computer.

Optical Character Reader (OCR):

This device is used to detect alphanumeric characters of either handwritten or typed text. These devices are used for large-volume processing applications such as scanning of utility bills of customers, credit cards of different companies etc.

Bar Code Reader:

Bar code reader is a type of scanning device which read the labels in form of special lines called bar. This device depends on the black and white lines of the Universal Product Code (UPC).

 Magnetic Ink Character Reader (MICR):

This device read the character which are printed by magnetizable ink. This device is use in banks for reading the cheque automatically by a machine and the store the data into the computer.


A joystick is a device that especially designs for moving the cursor, word, page, object and pictures from one point to another on point on the screen. It is mostly used in games and by a pilot to control the ailerons and elevators of an airplane, is a hand-held lever that pivots on one end and transmits its coordinates to a computer.

Light Pen:

The light pen looks like an ordinary pen, but its tip is light sensitive detector. When the tip of the pen touches the surface of the screen, the computer locates its position. The text writing or drawing can be directly performed on the surface of the display screen.

Computer Output devices

The entire computers peripheral which are used to provide data after processing in human readable for are called output devices. Most common examples of output devices are monitor, speaker and printer etc.

Monitor: -

A monitor is an output device which displays the images, text, and videos. The monitor is one of the most common output devices. It also some time called Visual Display Units. The monitor comes in different form and with different feature.

 Printer: -

The output device which provides the Hard copy of our document is called Printer. Printer prints whatever is on the monitor onto paper. Printers can print words, numbers, or pictures.

 Plotter: -

Plotter is also output printing device like printer. Plotter prints the vector graphic files and also prints line drawings through directly from command. Plotter use a pen, pencil, marker, or other writing tool to draw a design onto paper rather than any traditional toner or ink cortege.


What is Scanner and It’s Types?

Scanner is an input device which captures the data form hard copy such as photo, document, poster and then transfer in digital image which can be edited and store in the computer. Some time scanner used special software which helps us to scan the images. There are some other types of scanner for example barcode reader also read the barcode data by scanning the barcode.

Type Of scanner:

Flatbed Scanners

Flatbed scanners are desktop scanner and can easily attach with computer. This type of scanner has a glass platen inside the flip cover. We can put the images or document on this glass plate and then put the cover. Special software read our document and converts this document in to digital image and then stores the image in to the computer.

Photo Scanners

Scanning the photo require height resolution and color depth as compare to simple document. Photo scanner is a special type of scanner which is used for digitize film negatives or slides. Photo scanners include specialized technology so that they can deal with slides and negatives. These type of scanner also have built-in software to clean up old photos.

Sheet fed Scanners

In this type of scanner, the document needed to be scanned is inserted inside a slot that can be shaped either horizontally or vertically. These scanners are used for scanning the documents one page at a time. You cannot scan any document or book that may be great in thickness.

Portable Scanners

Portable scanners are very small in size and we can put in our pocket. Such as pen scanners can scan the text of a document line by line. They’re not give the high-resolution scans and not good for scanning photographs.

 What is Printer and its Types?

 The output device which provides the Hard copy of our document is called Printer. Printer prints whatever is on the monitor onto paper. Printers can print words, numbers, or pictures.

The two main types of printer are impact and non-impact printer.

Impact Printers

Impact Printers use a print head containing a number of metal pins, which strike an inked ribbon placed between the print head and the paper. Some print heads have only 9 pins to make the dots to build up a character; some have 24 pins, which produce a better resolution. 

Non-impact printers:

This type of printers does not operate by striking a head against a ribbon. Examples of non-impact printers include laser and ink-jet printers.

The different impact and non impact printer are following:

Dot Matrix Printer

This is very popular printer mostly used in offices. Dot matrix is one of the Impact printers. This printer prints text and also graphics on the paper by using dots to paper the desired shapes. It contains a Head which have some metal pins. When these pins strike an printer ribbon and produce dots on the paper. The speed of Dot-matrix printers mostly between 50 to 500 characters per second.

Ink Jet Printer

Inkjet printers are fall in non-Impact category. This type of printers is used in home and small offices. These types of printer are available on very cheap price and have a good quality output.

Inkjet printer can prints color and black and white both martial.

The inject printer have a small printing Head and inkjet cartridge. This cartridge has printing ink and this ink spray on paper through Head nozzles.

Laser Printers

Laser printers are also non-Impact Printer type. This type of printers uses a laser beam and dry powdered ink to produce a fine dot matrix pattern. This method of printing can generate about 4 pages of A4 paper per minute. The standard of print is very good and laser printers can also produce very good quality printed graphic images

What is Plotter and its Types?

Plotter is also output printing device like printer. Plotter prints the vector graphic files and also prints line drawings through directly from command. Plotter use a pen, pencil, marker, or other writing tool to draw a design onto paper rather than any traditional toner or ink cortege.

Drum Plotter

Drum plotter is also some time called Roller Plotter. This type of plotters has a drum or roller. The printing paper is attached on this drum or roller. This drum or roller rotates and a mechanical device known as Robotic Drawing Arm which are holds a set of colored ink pens or pencils draw lines on paper.

Flatbed Plotter

Flatbed plotter some time also called Table Plotter. In this type of plotter paper is spread and fixed on rectangular table and two robotic drawing arms of flatbed plotter pens or pencils drawing on that paper. This type of plotter has size of 20- by-50 feet. It is used in the design of cars, ships, aircrafts, buildings, highways etc.

Secondary /auxiliary Storage Devices

 Secondary storage which some time also called auxiliary storage is used to store the data after the processing. This storage is permanent data storage which may be internal or external. Some of the most common secondary storage devices are hard disk, floppy disk etc.

There are many type of Secondary storage devices are available user can be use any one depending o its requirement. Every secondary storage have different feature such that capacity, technology, speed etc.

Magnetic Tape Storage

Magnetic tape is a plastic material ribbon. The tape drive is an input/output device that reads, writes and erases data on tapes. The magnetic tape is usually use for backup purpose. This is a very inexpensive and store large amount of data. Magnetic tape is not suitable for data files that are revised or updated often because it stores data sequentially. Following are the different types of tapes.

Tape cartridge: A Tape cartridge shape like small plastic box and contain large strip of magnetic tape on which a permanent program is stored. Manufacture install data on the tape cartridge, which is only readable by the user (user can’t save any thing on it) as it behave like a ROM. Therefore it is known ROM cartridge.

Tape cassettes: -

A tape a cassette is exactly like an audiocassette. The data store on this cassette is also in sequential order to reach a specific point need to pass through all the data before that point.

Magnetic Disk Storage

Magnetic disks are a disk which is covered with a magnetic coating on which digital information is stored in the form of microscopic, magnetized regions. The disk surface is divided into concentric tracks (circles). Tracks are further divided into sectors, which hold a block of data. Magnetic disks are the most widely used storage medium for computers. Magnetic disks hold more data in a small place and have faster data access speeds.

 Types of magnetic disks include the following types:

Floppy disk: -

Floppy disk is a soft disk which some time also called diskettes. This is a portable disk which is small and lightweight. The user can store the data on it and then remove the disk. A special drive which is called floppy drive is used for read and writes the data on it. A floppy disk stores small amount of data such that 1.44 MB.

Hard disk: -

Hard disk is type of magnetic disk on which you can store large amount of computer data. This is called Hard disk because this is a magnetic disk (a round plate of Mattel) which is covered in Hard Mattel Box. Hard disks hold more data and are faster than floppy disks. A hard disk, for example, can store anywhere from 10 to more than 100 gigabytes.

Compact disk: -

Compact Disk which is shortly called CD is a round plastic disk of 4.75 inches in diameter. It provides read only secondary storage. This media is capable of sorting 650M of digitally encoded computer data, or 75 minutes of music. A special drive which is called CD-ROM is used for reading the data form CD.

Disk Cartridges

Removable disk cartridges are another form of disk storage for personal computers. They offer the storage and fast access of hard disks and the portability of diskettes. They are often used when security is an issue since, when you are done using the computer, the disk cartridge can be removed and locked up leaving no data on the computer.