A computer network uses communication equipment and communication links or communication networks to interconnect computer systems with different locations and autonomous functions, and follows certain rules to realize information exchange between computer systems.

From a technical perspective, computer network is the product of the integration of computer technology and communication technology.

Currently the largest and most widely used computer network is the Internet or the Internet.

Packet switching equipment can receive and forward data packets and is an important foundation for the Internet. It exists in many forms, the most typical ones being routers and switches.

Entities in a computer network must also follow some rules or conventions during data exchange. These rules or conventions are network protocols.

The agreement stipulates the type of information exchanged between entities, the meaning of each part of the information, the order of information exchange, and the actions to be taken when receiving characteristic information or abnormality occurs.

Any protocol will explicitly or implicitly define three basic elements:

It is to realize rapid information exchange between different hosts (core function-resource sharing)

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