The computer is widely used in all phases of society. In industry, business, education, medicine, nearly all walks of life, computers have made their appearance, providing great speed and accuracy for our work. Computers have been used in the home, offices, laboratories and research institutions, functioning as the most efficient and versatile instruments for calculating, sorting, filing, recording and distributing. Computers are indispensable to modern civilization. Without computers, our life and our society will undoubtedly suffer a big regression.

　　During the past five decades the computer has been rapidly advanced. Ever since the computer came into being, it has experienced the development of several generations, which are based respectively on vacuum tube, transistor and integrated circuit. Early computers were of great size, and had no match for the latest electronic computers in speed and accuracy. The Latter is capable of processing the most complicated information and reaching solution to problems in a fraction of time. At present, efforts are being made not only to bring the hardware to perfection, but also to improve the quality of the software.