CoMpUtEr NeTwOrKs

A computer network, often simply referred to as a network, is a collection of computers and devices connected by communications channels that facilitates communications among users and allows users to share resources with other users. Networks may be classified according to a wide variety of characteristics. This article provides a general overview of types and categories and also presents the basic components of a network.

Common types of computer networks may be identified by their scale.

Local area network

A local area network (LAN) is a network that connects computers and devices in a limited geographical area such as home, school, computer laboratory, office building, or closely positioned group of buildings. Each computer or device on the network is a node. Current wired LANs are most likely to be based on Ethernet technology, although new standards like ITU-TG.hn also provide a way to create a wired LAN using existing home wires (coaxial cables, phone lines and power lines).

^{A metropolitan area network}

^{(MAN) is a network that connects two or more local area networks or campus area networks together but does not extend beyond the boundaries of the immediate town/city. Routers, switches and hubs are connected to create a metropolitan area network.}

Wide area network

A wide area network (WAN) is a computer network that covers a large geographic area such as a city, country, or spans even intercontinental distances, using a communications channel that combines many types of media such as telephone lines, cables, and air waves. A WAN often uses transmission facilities provided by common carriers, such as telephone companies. WAN technologies generally function at the lower three layers of the OSI reference model: the physical layer, the data link layer, and the network layer.

Most people pick u their telelophone and call their friends or family members,upload and download files on the internet,create a networks to effficiently utilize resources and other forms of data comunation on a daily basis but they fail to appreciate telecommuncation.This is because they are ignorant of the history and principles of telecommunication.
The invention of the telephone which later transformed in telecommunication took several decades of dedicated scientist to invent.Scientist like Sir Charles Wheatstone, Sir Williams Cooke, Claude Chappe, Elisha Gray, Alexander Graham bells just a few to mention of.
One major controversy in the late 19th century was determining the patent right of the Telephone.Two great scientist Graham Bell & Elisha Gray both submitted the patent for the Telephone on the same day but Graham Bell submitted his patent 2 hours earlier before Elisha Gray.There were lot of law suite and court cases but Alexander Graham Bell's name was firmly etch on the historical time line has inventor of Telephone
After Gray's death in 1901 a note was dicovered in his laboratory.It stated :"The history of the Telephone will never be full written ......................It is partly hiden ..................and partly lying on the Earth and conscience of a few whose lips are sealed, some indeath and others by golden clasp whose grip is even tighter".
Other scientist now developed on the principles of Graham's telephone to invent what we now call Data Communication