Since the birth of the first computer in 1946, according to the electronic devices used in computers, the development of computers has roughly experienced four stages. Namely: the first generation, the tube computer with the tube as the main component (1946~1958); The electron tube is the basic electronic device; Use machine language and assembly language; Mainly used in national defense and scientific computing; The operation speed is thousands to tens of thousands of times per second. The second generation, transistor computer with transistor as the main component (1958~1964); Transistor is the main device; Operating system and algorithm language appeared in software; Operation speed of tens of thousands to hundreds of thousands of times per second. The third generation of computers used integrated circuits (1964~1971); Integrated circuits are widely used; Reduction in volume; The operation speed is hundreds of thousands to millions of times per second. Fourth generation computers used large-scale and very large scale integrated circuits (1971~). Large-scale integrated circuit as the main device; Operation speed of millions to hundreds of millions of times per second. At present, the computer has entered the stage of development of the fifth generation computer, which is different from the previous four generations in technology, concept and function. In short, with the development of computer technology, the volume of computers is getting smaller and smaller, and the capacity is getting larger and larger. More and more powerful, more and more convenient to use and maintain.