Computer have five generations on the basis of technology.
First generation of computer (1946-1959)
The first generation computer used vacuum tubes for calculation.vacuum tube were very expensive. These tubes produce a lot of heat that caused breakdown of the computer. It was an unreliable and expensive technology. The computer of this generation is very large in size and occupied space. Special room with air conditioner were required to place these computer.
Computer model of this generation
ENIAC
EDVAC
UNIVAC
IBM-701
IBM-650
Second generation of computer (1959-1965)
The second generation computer used transistor for calculation instead of vacuum tube. The computer of this generation were more fast, cheaper, consumed less power, more compact in size, more reliable and efficient than the first generation.
Computer model of this generation
IBM-1620
IBM-7094
CDC-1604
Third generation of computer (1965-1971)
Third generation computer used integrated circuit (IC's) in place of transistor. This development made computer smaller in size, reliable and efficient. In this generation remote processing,time sharing and multi-programing operating system were used .
Computer model of this generation
IBM-360 series
Honeywell-6000 series
TDC-316
Fourth generation computer (1971-1981)
Fourth generation computer used very large scale integrated(VLSI) circuit this is advance form of IC's. This generation of computer more reliable,compact and affordable. This generation of computer were portable, revolution of personal computer.
Computer model of this generation
DEC-10
IBM-650
STAR1000
Apple-1
Fifth generation computer (1980-till date)
The fifth generation computer used ultra large scale integration (ULSI) technology. This lead to the invention of microprocessor Chips having ten million electronic components. This generation is based on parallel processing hardware and artificial intelligence (AI). Artificial intelligence consist of robotics neural network,game playing, development of expert system to make decision in real life situation.
This generation of computer more reliable, compact, portable,fast and efficient working than other generation.
Computer model of this generation
Notebook
Desktop
Laptop
Ultrabook
Chroom book
Robots.