A network is a collection of computers connected to each other. The network allows computers to communicate with each other and share resources and information among the connected computers.

Computers on a network are sometimes called Nodes. Computers and devices that allocate resources for a network called Servers.
Types of Network
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- Local-Area Networks (LANs): The computers are geographically close together (that is, in the same building).
- Wide-Area Networks (WANs): The computers are farther apart and connected by telephone lines or radio waves.
- Campus-Area Networks (CANs): The computers are within a limited geographic area, such as a campus or military base.
- Metropolitan-Area Networks MANs): A data network designed for a town or city.
- Home-Area Networks (HANs): A network contained within a user’s home that connects a person’s digital devices.
- Global Area Networks (GANs): GAN is a model for supporting mobile communications across an arbitrary number of wireless LANs, satellite coverage areas, etc.
- Virtual Private Network ( VPNs ): A computer network in which some of the links between nodes carried by open connections or virtual circuits in some larger network (e.g., the Internet) instead of by physical wires. A VPN allows computer users to appear to be editing from an IP address location other than the one which connects the actual computer to the Internet.