Generation of computers details, how computer technology has progressed to its current state from ancestors. Thus, ‘Generation’ signifies the advancements in computer technology. In 600BC a manual device was used for purpose of calculation. With different generations of computer became cheap, powerful in computation and storage as in first generation vacuum tube technology was used, in second transistors, in third IC chip technology (integrating circuits to size of 5mm square called chip) and in present fourth generation VLSI (Very Large Scale Integration of circuits)chip technology is used. Fifth generation technology computers will use Artificial Intelligence and computers will be able to reason but it is still in research.