Computer

COMPUTER BASICS

Seema Sirpal

Delhi University Computer Centre

What is a Computer?

An electronic device that stores, retrieves,

and processes data, and can be

programmed

with

instructions.

A

computer is composed of hardware and

software, and can exist in a variety of

sizes and configurations.

Hardware & Software

The term hardware refers to the physical

components of your computer such as the

system unit, mouse, keyboard, monitor etc.

The software is the instructions that makes

the computer work. Software is held either

on your computers hard disk, CD-ROM,

DVD or on a diskette (floppy disk) and is

loaded (i.e. copied) from the disk into the

computers RAM (Random Access Memory),

as and when required.

Types of Computers

Mini and Mainframe Computers

Very

powerful,

used

by

large

organisations such an banks to control

the entire business operation. Very

expensive!

Personal Computers

Cheap and easy to use. Often used as

stand-alone computers or in a network.

May be connected to large mainframe

computers within big companies.

Hardware Components

Input Devices -- "How to tell it what to do“

- A keyboard and mouse are the standard way to

interact with the computer. Other devices include

joysticks and game pads used primarily for games.

Output Devices -- "How it shows you what it is doing"

- The monitor (the screen) is how the computer

sends information back to you. A printer is also an

output device.

Hardware Components

INPUT DEVICES

The Mouse

Used to ‘drive’ Microsoft Windows

The Keyboard

The keyboard is still the commonest

way of entering information into a

computer

Tracker Balls

an alternative to the traditional mouse

and often used by graphic designers

Hardware Components

INPUT DEVICES

Scanners

A scanner allows you to scan printed material

and convert it into a file format that may be

used within the PC

Touch Pads

A device that lays on the desktop and responds

to pressure

Light Pens

Used to allow users to point to areas on a

screen

Joysticks

Many games...