Introduction

Computer is an electronic data processing device that is capable of receiving input data, storing the set of instructions for solving problem and generating output with high speed and accuracy. Though, the word computer doesn’t have full form, it can be generalized in following form.

C: Commomly

O: Operated

M: Machine

P: Particularly

U: Used for

T: Trade

E: Education &

R: Research

The word computer is derived from the latin word computare. The word means to calculate.The first electronic computers were developed for scientists and mathematicians for solving the arithmetic problems. But nowadays, it is popular in almost every sectors like schools, colleges, offices, banks, factories, insurance companies, government offices, airlines activities, e.t.c.

Advantages of computer

1. Performance given by computer is 100% Accurate and reliable.

2. It is much faster than human being.

3. Many works termed as impossible for human is easily done by computer.

4. It is a versatile machine.

5. It is widely used in overall fields.

Some general Terms

Data: It is the facts related to people, places, events, e.t.c. which can in form of alphabets, numbers or alpha-numeric characters. E.g.: 45 & 15.It is input.

Instruction: It is to specify what must be done upon the input data. 45+15; adding (+) is the instruction.

Hardware: All the physical parts of computer which can be seen and touched are called hardware. It can be compared to the body of human. E.g. monitor, keyboard, C.P.U., mouse, e.t.c

Software: A seies of instructions or commands written in a form of program is called software. In other word, software is the group of programs which are the set of instructions.

E.g. Windows, Ms-Office, e.t.c.

Firmware: The programs stored in ROM during the time of manufacture by the manufacturers are called Firmware. It cannot be modified. Hardware is used to write program in ROM and available in read Only Memory chips.

Input devices: The devices which are used to feed data and instructions to the computer are known as input devices. The most commonly used devices are keyboard and mouse. Other devices like touch pad, light pen, track ball, joystick, and e.t.c. can be used as per requirement.

Output devices: The devices through which the computer gives output after required processing are called output devices. Output can be in two forms and they are hard output in papers and soft output on screen. E.g.: Monitor printer, plotter, and e.t.c.

Memory: Memory is the location where we can save huge amount of data and programs for present and future reference. Memory can be of two types namely Primary memory and Secondary memory. RAM and ROM is Primary memory where as hard disk, floppy disk, CDs, e.t.c. are secondary memory devices.