Before turning specifically to the local area network are: What is a computer network?
The computer network - is the combination of computers and various devices to exchange information between computers on the network without using any intermediate media.
All the diversity of computer networks can be classified on a group of characters:
1) The territorial distribution;
2) Departmental affiliation;
3) The speed of information;
4) The type of transmission;
As the prevalence of territorial networks can be local, global and regional. Local - this network, overlapping area of not more than 10 m2, regional - located in the city or area, global in a State or group of States, for example, the global network Internet.
As supplies are distinguished departmental and public networks. Institutional belong to one organization and located on its territory. The public network - a network used in government.
As the speed of information networks are divided into low, medium and high speed.
By type of transmission are shared on a network of coaxial, twisted pair on, optical fiber, with the transfer of information on the radio, infrared.
Computers can connect wires, forming a different network topology (star, bus, ring, etc.).
It should be distinguished from computer networks and network terminals (network terminal). Computer networks link computers, each of which can work independently. Terminal network typically associated powerful computers (maynfreymy), and in some cases, and PC devices (terminals), which can be quite complex, but outside the network of their work, or impossible or meaningless. For example, a network of ATMs and cash registers on the sale of airline tickets. We construct them on entirely different than computer networks, principles and even on other computers.
The classification networks there are two basic terms: LAN and WAN.
LAN (Local Area Network) - LAN, having closed the infrastructure to enter the service providers. The term «LAN» can describe and small office network and a network of a large factory, occupying several hundred hectares. Foreign sources provide an even closer assessment - about six miles (10 km) radius, using high-speed channel.
WAN (Wide Area Network) - A global network covering large geographic regions, which include a local area network, and other telecommunications networks and devices. Example WAN - a network packet switching (Frame Relay), through which can «talk» between different computer seti.1
The term «corporate network» is also used in the literature to refer to combine multiple networks, each of which can be built on various technical, policy and information principles.
The above types of networks are closed networks, access is allowed only a limited number of users for whom work in such a network is directly related to their profession. Global network-oriented services to all users.