What Are The Four Generations Of Computers?

First Generation (1951 to 1958)In first generation computer used the vacuum tubes. An 1943 ENIAC, the Electronic Numerical Integration And Calculator was design. In this calculator there were 18000 vacuum tubes and it consumed 150 kilowatt of power. The weight of ENIAC was 30 tons. ENIAC was programmed physically connecting electronic wires in the proper order.

Second Generation (1959 to 1964)With the advent of transistor technology, the second generation of comport came into existence. Transistors were small, fast and more reliable for less power. Computers were developing with the help of transistor that were able to perform a single operation in microseconds and were capable to store data in kilos of bytes.

These machines used English language like language known as high level language for programming such as FORTRAN and COBOL.Third Generation (1965 to 1970)
In sixties, the integrated circuits appeared into the field of microelectronics. Many components like transistor, diodes and capacitances were growing up on the single slice of semiconductor. The components fabricated on integrated circuits were so small that many cases that were hardly visible.

Third generation computers used more versatile programmed like real time operating system, Multiprogramming and database management.During this period the software industry introduced to emerge programs to perform payroll, building and other business tasks.

Fourth Generation (1971 to present)
The development of the microprocessor chip, which contains an entire central processing unit on a single silicon chip, led to construction of inexpensive computers. These computer used a large scale integrated circuits and reduced the size and cost of computers. The first 8-bit microprocessor was developed by Intel Corporation in 1973.they could perform operation of 8 bit words.

The first generation  1946-1956.mainframes.  
The second generation computers.  1956-1964,  
Mainframes third generation 1964-1970. mainframes, and minicomputers.
The fourth generation, 1970- present.maINframes, minicomputers, microcomputers. kapor

First generation was the vacuum tubes.
The second generation was the transistors.
The third generation was the IBM System/360.
The fourth generation was the microprocessor.