what is lan: It is a privately-owned network and stands for local area network. A network is a group of computers and other devices connected so they can pass information back and forth. The local area network (LAN) is a network which is designed to operate over a small physical area such as an office, factory or a group of buildings up to a few kilometers in size. LANs very widely used in a variety of computers to share resources (e.g., printers) and exchange information.

LAN Definition
The personal computers and workstations in the offices are interconnected via LAN to share resources. The resources to be shared can be hardware like a printer or softwares or data. A LAN is a form of local (limited-distance), shared packet network for computer communications. In LAN all the machines are connected to a single cable.  The data rates for LAN range from 4 to 16 Mbps with the maximum of 100 Mbps.

Know more: how to set up a LAN?

The term LAN can also refer just to the hardware and software that allows you to connect all the devices together. In this sense, Local Talk is one kind of LAN, Ethernet is another. (AppleTalk is the protocol for Local Talk.) 

The components used by LANs can be divided into cabling standards, hardware, and protocols. Various LAN protocols are Ethernet, Token Ring: TCP/IP, 5MB, NetBIOS and NetBeui, IPX/SPX, Fiber Distributed Data Interchange (FDDI) and Asynchronous Transfer Mode (ATM).

Maecenas aliquet accumsan

Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos hymenaeos. Etiam dictum tincidunt diam. Aliquam id dolor. Suspendisse sagittis ultrices augue. Maecenas fermentum, sem in pharetra pellentesque, velit turpis volutpat ante, in pharetra metus odio a lectus. Maecenas aliquet
Or visit this link or this one