Computer network is a form of electronic communication. The network might either be a small or a large number of computers which are linked at different places. The network may be divided in two categories which is based on the operational area of the network.

• Local Area Network (LAN)
• Wide Area Network (WAN)

Local Area Network (LAN):
A Local Area Network is a small group of computers (generally about 3 to 50 terminals) interconnected together and located inside a single building of same organization or institution, or within a limited area.

All the terminals are connected with a main computer which is widely known as server. LAN supports a range of around 10km. Computer terminals (workstations) are attached to the server (main computer). The server stores all sorts of data, files, programs, and different software, and provides them to the workstation. LAN system can have more than one server. A device called NUI (Network Interface Unit) establishes the link between networks. All these are connected through cables, which are similar to ‘Cable Television’ connection.

Features of LAN (Local Area Network) – There are several features of LAN (Local Area Network) are given below-

1. Multiuser – It allows several users to share the server at one time and have direct access to hardware and software. Any user can get the printout from a printer by using certain set of commands.
2. Security – The LAN (Local Area Network) system does not provide best or foolproof security system. However, it had in-built security features and access to the users can also be controlled.
3. Mobility – The terminals can be changed and placed at desired locations. Addition and removal of terminals is very simple.
4. Communication – The nodes (terminals) can be used to transfer messages that is the nodes may perform a function, which is similar to that of an intercom.

Drawbacks – The system has a major drawback in that entire functioning is dependent on a server. Thus, any fault or breakdown in the server affects the complete functioning, which means that the nodes connected to it, will not function.