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Computer network

network that allows computers to share resources and communicate with each other / From Wikipedia, the free encyclopedia

A computer network is a group of two or more computers that are linked together. Networks are usually used to share resources, exchange files or communicate with other users.

Typical library network, in a branching tree map and controlled access to resources

A network is a set of nodes connected by communication links. A node can be a computer, printer, or any other device capable of sending or receiving data from or to the other node in the network.[1]

Other devices are often needed for the network to work correctly. Examples for such devices include hubs and switches. Different kinds of network can be connected to each other with a router. In general, networks that use cables to connect can operate at higher speeds than those using wireless technology.

Computers in a network can be near each other, or far. A Local Area Network (LAN) connects computers which are close together. Building a LAN is easier than connecting different networks (by a Wide Area Network). The largest Wide Area Network is the Internet.

Computers can be part of several different networks. Networks can also be parts of bigger networks. The local area network in a small business is usually connected to the corporate network of the larger company. These connections may allow access to the Internet. For example, a shop may use it to show merchandise on its Web site through a web server, or to convert received orders into shipping instructions.

A network must be connected with appropriate hardware. This can be wired or wireless. For a simple LAN, computers, media and peripherals are sufficient. WANs (wide area networks) and some large LANs (local area networks) need some additional devices like a bridge, gateway or router to connect different small or large networks.

A network needs a communication protocol (a system for exchanging messages between computing systems.) Microsoft Windows, Linux and most other operating systems use TCP/IP. Apple Macintosh computers used Appletalk in the 20th century, but use TCP/IP now.