Five generations of computers

Generation may be called a change in technology how a computer is/was being used. In very past, the term generation was used to distinguish between varying hardware technologies under use. But in modern era, generation includes both changes in hardware and software, which together make up an entire computer system.

The computer is firstly designed by Charles Babbage.He designed it in form of an Analytic Engine and upon this design the basic framework of the computers are based on.

There are totally five computer generations known till date. All five generations are described below-

First Generation of Computers (1942-1955)

The beginning of commercial computer age is from UNIVAC (Universal Automatic

 Computer). It was developed by two scientists Mauchly and Echert at the Census

 Department of United States in 1947. The first generation computers were used during 

1942-1955. They were based on vacuum tubes. Examples of first generation computers are

 ENIVAC and UNIVAC-1.

Second Generation Computers (1955-1964)

The second generation computers used transistors. The scientists at Bell laboratories 

developed transistor in 1947. These scientists include John Barden, William Brattain

 and William Shockley. The size of the computers was decreased by replacing vacuum 

tubes with transistors. The examples of second generation computers are IBM 7094 series, 

IBM 1400 series and CDC 164etc.

Third Generation Computers (1964-1975)

The Third generation computers used the integrated circuits (IC). Jack Kilby developed the

 concept of integrated circuit in 1958. It was an important invention in the computer field. The 

first IC was invented and used in 1961. The size of an IC is about ¼ square inch. A single IC

 chip may contain thousands of transistors. The computer became smaller in size, faster, more

 reliable and less expensive. The examples of third generation computers are IBM 370, IBM 

System/360, UNIVAC 1108 and UNIVAC AC 9000 etc.

Fourth Generation Computers (1975-Present)

The fourth generation computers started with the invention of Microprocessor. The 

Microprocessor contains thousands of ICs. Ted Hoff produced the first microprocessor in 

1971 for Intel. It was known as Intel 4004. The technology of integrated circuits improved

 rapidly. The LSI (Large Scale Integration) circuit and VLSI (Very Large Scale Integration)

 circuit was designed. It greatly reduced the size of computer. The size of modern 

Microprocessors is usually one square inch. It can contain millions of electronic 

circuits. The examples of fourth generation computers are Apple Macintosh & IBM PC.

Fifth Generation Computers (Present & Beyond)

Scientists are working hard on the 5th generation computers with quite a few

 breakthroughs. It is based on the technique ofArtificial Intelligence (AI). Computers 

can understand spoken words & imitate human reasoning. Can respond to its

 surroundings using different types of sensors. Scientists are constantly working to 

increase the processing power of computers. They are trying to create a computer

 with real IQ with the help of advanced programming and technologies. IBM

 Watson computeris one example that outsmarts Harvard University Students. The 

advancement in modern technologies will revolutionize the computer in future.