
A computer network is a number of computers linked together to allow them to share resources. Networked computers can share hardwarehardware: the physical components of a computer, softwaresoftware: a general term used to describe an application or a program and datadata: information without context, eg a list of students with numbers beside their names is data, when it's made clear that those numbers represent their placing in a 100 metre race, the data becomes information.
Most computer networks have at least one server. A server is a powerful computer that provides one or more services to a network and its users. For example, file storage and emailemail: electronic mail - a message written or typed on a computer and sent electronically rather than by post.
There are two main types of network:
A LAN covers a small area such as one site or building, eg a school or a college.

LAN - Local Area Network
A WAN covers a large geographical area. Most WANs are made from several LANs connected together.

WAN - Wide Area Network