Also called Gateway equipment (gateway) is used to connect multiple logically separated networks, and the so-called logical network represents a single network or subnet. When data is transmitted from one subnet to another, it can be done through the routing function of the router.

External network:

A wide area network (WAN) is also called a remote network. It usually spans a large physical range, covering from tens of kilometers to thousands of kilometers. It can connect many cities or countries, or span several continents and provide long-distance communication, forming an international long-distance network.

Intranet:

Local area network refers to a group of computers interconnected in a certain area. Generally speaking, it is only a few kilometers away from Fiona Fang. LAN can realize file management, application software sharing, printer sharing, workgroup scheduling, e-mail and fax communication services and other functions. LAN is a closed type, which can be composed of two computers in an office or thousands of computers in a company.

In order to better understand the picture below, the red box is the external network and the internal network is the blue box. The hole in the middle is the router.