DEFINING LAN.

Local Area Network (LAN) is a group of computers within a small radius, interconnected to each other through cable or a wireless medium. Amongst all computer networks, LAN covers comparatively small range of distance. They are confined to a single building or a group of buildings like a home, school, college or an office building. Mostly,LANs are used in personal computers and work cubicles. LANs enable multiple users to use a single hardware device like a printer or a scanner, allows file-sharing between users, enables communication through e-mail, instant messaging, etc. There are different kinds of LANs. They can be segregated from one another on the basis of topology, protocol and media used. Topology refers to the way in which the communicating devices are linked to each other such as ring(ring like structure) topology, star(star like structure) topology, etc.

The different cable media used in LANs are Co-axial cable, Optical fibre cable,twisted type cable, etc. Nowadays, wireless media known as wireless LAN (WLAN) is also used. It uses high frequency radio waves. Ethernet is the most common type of LAN for PCs. It can be linked to the communicating devices ,both through cables and wireless media. LANs possess high data transfer rates but are bounded by distance. Also, there is a curb on the number of computers that can be attached to a single LAN.