UGC NET JRF Unit 8 - ICT NET Materials (UGC NET Paper I)

  UGC NET JRF Unit 8 ICT NET Materials (UGC NET Paper I)

Unit-VIII Information and Communication Technology (ICT)

• ICT: General abbreviations and terminology.
• Basics of Internet, Intranet, E-mail, Audio and Video-conferencing.
• Digital initiatives in higher education.
• ICT and Governance.

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• Functionalities of a computer
• Applications of Computer
• Classification of Computers:
• Software
• Number System
• Number Conversion
• Decimal to Binary System
• Binary to Decimal System
• Networking
• Five components:
• Sender Computer
• Communication Channel (Telephone Cables or wireless device)
• Classification based on Geographical Coverage:
• Advantages of an Intranet:
• Internet
• Various features of a Web Browser are:
• ELECTRONIC MAIL (e-mail)
• Protocols:
• Web Conferencing
• E-Commerce
• Types of E-Commerce:
• COMPUTER SECURITY
• Abbreviations in computer or ICT domain
• Talk to a Teacher:
• Campus Connectivity
• Digital Initiatives other than Higher Education
• e-Pathshala;
• e-Basta:
• Sugamya Pustakalaya:
• Diksha:
• Saransh:
• Governance:
• E-Governance:
• Objectives of e-Governance
• Advantages of e-Governance
• Scope of e-Governance
• Government to Government (G2G)
• Government to Citizen:
• booking and cancellation of tickets,
• issue and renewal of driving licences.
• transfer of vehicles,
• payment of fees and taxes for vehicle registration.
• Citizen to Government
• Government to Government (G2G)
• Government to Business (G2B)
• Emerging Areas for e-Governance in India
• Health and Sanitation
• ICT in energy conservation

Information & Communication Technology (ICT)

• Computer: A computer is a truly amazing machine that performs a specified sequence of operations as per the set of instructions (known as programs) given on a set of data (input) to generate desired information (output).

A complete computer system consists of four parts:

• Hardware: Hardware represents the physical and tangible components of the computer.
• Software: Software is a set of electronic instructions consisting of complex codes (Programs) that make the computer perform tasks.
• User: The computer operators are known as users.
• Data: Consists of raw facts, which the computer stores and reads in the form of numbers.

Functionalities of a computer

Any digital computer carries out five functions in gross terms:

• Takes data as input.
• Stores the data/instructions in its memory and use them when required.
• Processes the data and converts it into useful information.
• Generates the output
• Controls all the above four steps.

The following features characterize this electronic machine:

• Speed
• Accuracy
• Storage and Retrieval
• Reliability
• Flexibility
• Low cost
• Repeated Processing Capabilities

Applications of Computer

Following list are various applications of computers in today's arena:

• Business
• Banking
• Insurance
• Education
• Marketing
• Health Care
• Engineering Design
• Military
• Communication
• Government

Following are the main five generations of computers

• First Generation (1946-1959)- Vacuum tube based
• Second Generation (1959-1965)- Transistor based
• Third Generation (1966-1971)-Integrated Circuit based
• Fourth Generation (1971-1990)-VLSI microprocessor based
• Fifth Generation (1980-onwards) ULSI microprocessor based

• First Generation (1946-1959)- Vacuum tube based

• Second Generation (1959-1965)- Transistor based

• Third Generation (1966-1971)-Integrated Circuit based

• Fourth Generation (1971-1990)-VLSI microprocessor based

Fifth Generation (1980-onwards) ULSI microprocessor based

Computer hardware consists of the following components:

• CPU and
• Peripheral (Input & Output Devices)

1. CPU (Central Processing Unit);

• CPU is considered as the brain of the computer. It performs all types of data processing operations, stores data, intermediate results and instructions (program). It controls the operation of all parts of computer.

The relationship between different hardware Components

[A] CPU itself has following three components:

• ALU (Arithmetic Logic Unit): When the control unit encounters an or instruction that involves mathematical calculation. decision/logic, it passes the control to the second component, i.e., the arithmetic logic unit (ALU). The ALU includes a group of registers - memory locations built directly into the CPU that are used to hold data that are being processed by the current Instruction.
• Registers: The register is the smallest high-speed storage area in the CPU. All data must be represented in a register before it can be processed.
• Control Unit: This unit controls the operations of all parts of computer but does not carry out any actual data processing operations

[B] Primary memory consists of mainly two types of memories:

Random Access Memory (RAM): 

• RAM is the internal memory of the CPU for storing data, program and program result. It is read/write memory which stores data until the machine is working. As soon as the machine is switched off, data is erased. RAM is volatile, Le. data stored in it is lost when we switch off the computer or if there is a power failure. Hence a backup uninterruptible power system (UPS) is often used with computers. RAM is small, both in terms of its physical size and in the amount of data it can hold.

There are mainly three types of RAM available:

• Dynamic Random Access Memory (DRAM): A type of physical memory used in most personal computers. The term dynamic indicates that the memory must be constantly refreshed2 (reenergized) or it loses its contents. This type of memory is more economical.
• Static Random Access Memory (SRAM): A type of memory that is faster and less volatile than DRAM, but requires more power and is more expensive. The term static is derived from the fact that it does not need to be refreshed like DRAM
• Synchronous Dynamic Random Access Memory (SDRAM): A type of DRAM that can run at much higher clock speeds.

Read Only Memory (ROM): 

• The memory from which we can only read but can not write unit This type of memory is non-volatile The information is stored permanently in mach memories during manufacturer. A ROM, stores such instructions that are required to start a computer. This operation is referred to as bootstrap There are mainly three types of ROM available:

• MROM (Masked ROM): The very first BOMs were hard-wired densees that contained a priprogrammed set of data or Instructices. These kinds of ROMs are known as masked ROMS which are inexpensive

• EPROM (Erasable and Programmable Read Only Memory): The EPROM can be erased by exposing it to ultraviolet light for a duration of up to 40 minutes. Usually an EPROM sr achieves this function

• EEPROM (Electrically Erassable and Programmable Read Only Memory): The EEPROM is programmed and erased electrically It can be erased and reprogrammed about ten thousand times. Both erncing and programming take about 4 to 10 ms (milli second).

Memory

• A memory is just like a human brain. It is used to store data and instructions. Computer memory is the storage space in computer where data la to be processed and instructions required for groceening are stored. The memory is divided into large number of small paris called cells. Each location or cell has a unique address which varies from sero to memory stas m

Memory is primarily of three types-

• Cache Memory: It is a very high speed semiconductor memory which can speed up CPU. It acts as a buffer between the CPU and main memory.
• Primary Memory/Main Memory: Primary memory holds only those data and instructione on which computio la cumsently working. It has limited capacity and data is lost when power is switched off
• Secondary Memory: This type of memory is also known as external memory or non-volatile. It is slower than main memory. These are used for storing data Infomation permanently
• A. Secondary Storage (External Storage Devices): Floppy diskettes, hand dink,tapes and optical disks come under the category of extemal storage devices or ancillary storage devices. These devices are very sensitive to environmental conditions (humidity and temperature) as well as to extemal magnetic Selds and need to be stored carefully Floppy Disc Floppy disks are primarily used on PCs. Information on a floppy disk te recorded in the magnetized states of particles of tron oxides evenly placed upon concentric circles known as tracks

• Hard Disk: It is a non-removable enclosed magnetic disk included in moet PCs. Ir contains a stack of metal platters, each coated with iron oxide, that spin on a spindle and the entire unit is encased in a sealed chumbee
• Magnetic Tape: This is plastic tape, usually made of Mylar that is coated with tron odde, thereby enabling the introduction (writing); retention (memory) and reading of magnetically recorded information. The best use of tape storage in for data that you do not use very often.

2. Peripherals:

• Peripheral devices are devices connected to the computer externally. If a peripheral device is disconnected, the computer will still be able to work only functione performed by this peripheral device will not be available.

Mainly there are following types of peripheral devices:-

• A Input Devices (How to tell in what to do): This unit makes link between user and computer. The input devices translate the information into the form understandalile by computer. 
• B.Keyboard-The most common and very popular input device which helps in leputting data to the computer
• C. Mouse-Mouse is the most popular pointing device and cursor control device having a small palm size box with a round ball at its base which senses the movement of mouse atud sends corresponding signals to CPU when the mouse louitums are pressed. 
• D.Joy Stick To move cursor positions on a monitor screen. It is mainly used in Computer Aided Designing (CAD) and playing computer games. 
• E. Light pen-It is used to select a displayed menu item or draw pictures on the monitor
• F. Track Ball-Mostly med in notebook or laptop computer, instead of a mome. This is a ball which is half inserted and by moving fingers on ball, pointer can be moved
• G. Scanner A scanner allows you to scan printed material and convert it into a file format that may be used within the PC.
• H. Digitizer It converta analog information into digital form.
• 1. Microphone-3Microphone la an inpur device to input sound that is then stored in digital form
• J. Magnetic Ink Card Reader (MICR)-MICR amput device is generally used in banks because of a large number of check to be processed every day.
• K. Optical Character Reader (OCR)-OCR scans text optically character by character, converts them into a machine readable code and stores the teast on the gatem memory
• L Bar Code Reader A device used for reading bar coded data (data in form of light and dark lines). Bar coded data is generally used in labeling goods, nunibeeting the books.
• M. Optical Mark Reader(OMR) A special type of optical scanner med to recognize the type of mark made by pen or pencil.
• N. Output Devices (How it shows you what it is doing) Output devices translate the computer's output to the form understandable by users
• O Monitors : Monitors commonly called an Vinual Display Unit (VDU), are the main output device of a computer. It forms images from tiny dots, called pixels that are arranged in a rectangular form. The sharpness of the image depends upon the number of pixels

There are two kinds of viewing screen used for monitors,

• Cathode Ray Tube (CRT): The CRT display is made up of small picture elements called pixels. The smaller the pixels, the better the image clarity, or resolution.
• Flat Panel Display: The flat-panel display refers to a class of video devices that have reduced volume, weight and power requirement in comparison to the CRT Printer: Printer is an output detrice, which is uned to print information on paper
•  Impact Printers: The impact printars pelut the characters by striking them on the ribbon which is then pressed on the paper
• Non-Impact Printers: Non-impact printers print the characters without using ribbon. These printers prints complete page at a time, so they are also called as Page Printers. Laser Printers, Iniget Printers

Data: 

• Data can be defined as a representation of facts, concepes or instructione in a formalized manner which should be suitable for communication, interpretation, or processing by human or electronic machine.

Information: 

• Information is organizeit or classified data which has some meaningful values for the receiver. Information is the processed data on which decisions and actions are based

Data Processing Cycler Data processing in the re-structuring or re-coderling of data by people or machine to increase that usefulness and add values for particular purpose. Data processing consists of baile steps input, processing and output. These three steps constitute the data processing cycle

Input Input data is prepared in some contendsen form for processing. The form will depend on the processing machine For example, when slectronic computers are used, the input data could be recorded on any one of several types of input medium, such as magnetic disks, tapes and soon.

Processing - In this step input data is changed to produce data in a more umeful form. For example, paychecka may be calculated from the time cards, or a summary of sales for the month may be calculated from the sales orders

Output The result of the proceeding processing step is collected. The particular form of the output data depends on the use of the data. For example, output data may be pag-checks for employees.

Language Proceенн

Assembler: This language processor converts the program written in assembly language into machine language

Interpreter: This language processor converts an HLL. (High Level Language) program into machine language by converting and executing in line by line

Compiler: It siso converts the HLL program into machine language, but the conversion manner is different. It converts the entire HLL program in one go, and reports all the errors of the program along with the line numbers

Clamification of Computers:

Computers can be broadly classified by their speed and computing power

Sr. No.

Type

1

Specifications

PO (Person ET

It is a single ser computer system having moderatsty powerful microprocessor

#

WorkStation

3

Mina Computer

It is sho a single user computer system which is similar to personal computer bot have mors powerful microprocessor.

4

Main Frame

It is a milti-user computer system which is capable of supporting hundreds of users simultaneoush: Software technology is different fromminicompoter

It is a multi-usse computer system which is capable of supporting hundreds of mars samitaneously: Software technology la different fronsminicomputer

5

Superenmput

It is an extremely fast computer which can execute hundreds of millions of instructions per secund

Following are the main memory storage units

8.N

Unit

Description

Bit (Binary Digit)

A binary digit is logical 0 and 1 representing a pasanve or an active state of a component in en electric circuit

Nibbla

A group of 4 hits is called nibble.

Вуте

A group of 6 bits in called byte. A byte is the smallest unit which can represent a data item or a character (hyte 8 bits

4

Word

A computer word, like a byte, is a group of fixed number of bits processed as a unit which varies from computer to computer hat is fixed for each computer. The length of a computer word is called word-alas or word length and it may be as small as fi bira or may be au long au 06 hita. A computer stores the information in the form of computer words

Few higher storage units are following

S.No Unit

Description

1

Kilobyte (kb)

1 KB-1004 Вулеs

Megabyte (MB 1

MB-1024 KB

Gigabyte (GB)

1GB = 1024MB

Terabyte (TB

1 TB = 1024 GB

Petabyte (PB)

1FB = 1024TB

Software

Software software represents the set of programs that govern the operation of a computer system and make the hardware run

. There are two types of software

System Software The system software is collection of programa designed to operate, control, and extend the processing capabilities of the computer itself. System software are generally prepared by computer manufactures. System software serves as the interface between hardware and the end weers. Examples: Operating System. Compilers Interpreter, Assembler etc.

Application Software: It is the net of programa necessary to carry out operations for a specified application.

Application software can subdivide into three calingories

A. Packages

Packages

Word Processing

A package that process textual matter and creates organized and flawless documents

Spreadsheets

An electronde spreadsheet is a program that accepto data in a tabular form and allow users to manipulate, calculate, analyas data in the desired manner.

Database Management Systems

DBMS is a package that can handle and manage bulk of stored data

Desktop Publishing Software

Handles page layout by combining the functions of a traditional typesetter and a layout artist

Graphics, Multimedia and Presentation

Application software that manipulates inages known as Graphics software.

applications

B. Utilities: Utilities are those application programs that assist the computer by performing housekeeping functions like backing op disk or scanning virises etc.

Utilities

Text Editor

Program is used for creating, editing text files.

Backup Utility

Program facilities the backang-up of disk.

Compression Utility

Large tiles can be compressed so that it takes less storage are

Disk Defragmentor

It speeds up disk accees by rearranging the files and free space on your computer.

Antivirus Software

It scans yours disk for viruses and removes them if any virus is foamd

Customized Software: This type of anftware is tallormade software according to a user's requirement.

Number System

When we type some letters of words, the computer translates them in numbers as computers can understand only numbers. A computer can understand positional number system where there are only a few symbols called digits and these symbols represent different values depending on the position they occupy in the mimber

A value of sach digit in a number can be determined ming

The digit

The position of the digit in the number

The hase of the number system (where base is defined as the total number of digits available in the number system)

1. Decimal Number System: The number system that we use in our

day-to-day life is the decimal number system. Decimal number system has base 10 as it uses 10 digits from 0 to 6. In decimal

number system, the successive positions to the left of the decimal poin repressant units, teens, hundreds, thousands and soon.

2. Binary Number System. Uses two digita, 0 and 1, also called base I number system Each position in a binary mamber represents power of the base (2) Last position in a binary number represen