Computer network technology is the product of the combination of communication technology and computer technology. A computer network is a collection of scattered and independent computers interconnected according to network protocols. The connection medium can be cable, twisted pair, optical fiber, microwave, carrier wave or communication satellite. Computer network has the function of sharing hardware, software and data resources, and has the ability of centralized processing, management and maintenance of data resources. Computer networks can be classified according to different standards such as network topology, network coverage and interconnection distance, network data transmission, network system owners and service objects. Generally divided into: (1) local area network; (2) people; (3) WAN. The geographical scope of local area network is generally within 10 km, and it belongs to a small purse seine formed by a department or a group, such as a school, a unit and a system. WAN covers a large area, generally from tens of kilometers to tens of thousands of kilometers, such as a city, a country or an intercontinental network. At this time, the transmission equipment and media for communication are generally provided by the telecommunications department, which can realize a wide range of resource sharing. Metropolitan area network is between local area network and wide area network, and its scope usually covers a city or region, ranging from tens of kilometers to hundreds of kilometers.

A computer network consists of a set of nodes and chains. There are two types of nodes in the network: transmission nodes and access nodes. Communication processor, concentrator and terminal controller belong to transmission nodes, and transmit and exchange transmission information in the network. Host and terminal are access nodes, and they are the source nodes and target nodes of information transmission.

Computer network technology has realized resource sharing. People can access any resources on the Internet in the office, at home or anywhere else, which greatly improves work efficiency and promotes the development of office automation, factory automation and home automation.

2 1 century has entered the era of computer network. With the great popularity of computer networks, computer applications have entered a higher level, and computer networks have become a part of the computer industry. The new generation computer integrates the network interface into the motherboard, and the network function is embedded into the operating system. The construction of intelligent building and computer network wiring are carried out at the same time, in the same place and in the same scheme. With the close combination and synchronous development of communication technology and computer technology, China's computer network technology has developed rapidly.