The term actually has many different meanings depending on the person, company, or context in which it is being used. Basically, it is a collection of two or more computers and associated devices that are linked together with communications equipment. Once connected, each part of the network can share the software, hardware, and information contained in the other parts.
The most common types of network are LANs (Local Area Networks, in which the computers share the same office space, room, or building) and WANs (Wide Area Networks, in which LANs are connected at different geographic locations by telephone lines or radio waves, as in wireless communications). Network connections are established by twisted-pair cable, coaxial cable, fiber-optic cable, connectors, or NICs (network interface cards). Network computing depends on protocols that work with a variety of operating systems and network hardware (see: IEEE and ISO). When you hear someone talking about "sharing network resources," they are referring either to client/server networks or peer-to-peer networks.
Also, you may hear Internet companies refer to their "network of Web sites," a group of associated sites that's analogous to a television network or cable TV network. If you have a small business that uses a network for Internet access and file sharing, be sure to have a firewall installed, to protect yourself from unauthorized access.
NetLingo Classification: Net Technology