COMPUTER GENERATION
You know that the evolution of computer started from 16th century and resulted in the form of that we see today.The present day computer,however, has also undergone rapid change during the last fifty years.Computer are classified into different generation.They are:
1.First Generation Computer(1943-1958):-
First generation of computer used Therm ion valves.These computer were large in size and writing programs on them was difficult..They use vacuum tubes as memory device and they have 1 to 4KB storage capacity.They use machine level programming language.

2.Second Generation Computer(1959-1965):-
Around 1955 a device called Transistor replaced the bulky electric tubes in the first generation computer.Transistors are smaller than electric tubes and have higher operating speed.They have no filament and require no heat inf. Manufacturing cost was also very low.Thus the size of the computer got reduced considerably.

3.Third Generation Computer(1966-1973):-
The third generation computers were introduced in 1996.They used Integrated Circuits(Ics).These are popularly known as chips.A single IC has many transistors,registers and captious built on a single thin slice of silicon.

4.Fourth generation computer (1974-1990):-
The present day computers that you see today are the fourth generation computers that started around 1974.It uses large scale Integrated Circuits(LSIC) build on a single silicon chip called microprocessors.Due to the development of microprocessor it is possible to place computer's central processing unit(CPU) on single chip.These computers are called microcomputers.Later very large scale Integrated Circuits(VLASIC) replaced Slicks.

5.Fifth Generation Computer(1990-upward):-
The computers having artificial intelligence and high processing capacity undergoing on the development stage from 1990 are said to be fifth generation computer.