After the first mechanical computer, the design of computer evolved over a period of time. They were classified into generations.
First Generation Computer – The U.S Census Bureau developed the first business computer in the year 1951. This computer was called Universal Automatic computer (UNIVAC). It used vacuum tube circuits for processing. The computer that used vacuum tubes circuits where called the first generation computer. The vacuum tube circuits contained a filament that was heated to emit the electrons.
Second Generation computer – Bell Labs of U.S.A invented transistors that were instead used of vacuum tubes. Transistors are electronics circuit s that are small in size and do not require any heating for emitting electrons. The computers that used transistors were called the Second Generation computer.
Third Generation computer – The Third Generation computer used Large Scale Integrated (LSI) circuit for processing. The LSI circuits were invented in mid 1960′s. LSI circuits integrate several circuits’ components into a single chip.
Fourth Generation computer – Very Large scale Integrated (VLSI) chips were invented in the year 1969. The computers that used VLSI chips were called the Fourth generation computer.
Fifth Generation computer – Recent research has focused on developing “Thinking Computers”. These computers are called fifth generation computer
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