What is a computer?

The term computer is used to describe a device made up of electronic and

electro mechanical components. The computer itself cannot perform any task

and is referred to as hardware.

Any computer system consists of two elements :

1)Hardware

2)software

Software : Software is used to describe the instructions that tells the computer

how to perform a task. Software is categorized into 2 types

1) System softwares ( eg . operating systems, compilers, editors etc)

2) Application softwares ( MS-word, excel, accounting packages etc)

Hardware : The physical components which you can see, touch and feel in

the computer system are called hardware Eg monitor, keyboard, mouse,CPU etc

    The computer systems are of different types we can classify them as follows:

8-bit

 example : 8085 microprocessor

16-bit

 example : 8086, 286, 386 processor

32-bit

 example : 486

64-bit

 example : Pentium – II

The internal parts like registers and ALU use data in 8-bits in a 8 bit processor and so in a 16 bit and 32 bit processor the use 32 bit data.....the BUS which carries data from one part of a processor to another has 8-lines in a 8 bit processor,16 lines in a 16 bit and 32 lines in a 32 bit one.....because all these bits have to be transmitted simultaneously. The variation in these bits results in the variation of its speed size and capability.