Data networks continue to evolve in complexity, use, and design. A computer network is identified by the following specific characteristics:

Different types of networks are given different descriptive names. An individual network usually spans a single geographical area, providing services and applications to people within a common organizational structure. This type of network is called a Local Area Network (LAN). A LAN can be made up of multiple local networks.

All of the local networks within a LAN are under one administrative control group. This group enforces the security and access control policies of the network. In this context, the word Local refers to local consistent control rather than being physically close to each other. Devices in a LAN might be physically close, but this is not a requirement.

A LAN can be as small as a single local network installed in a home or small office. Over time, the definition of a LAN has evolved to include interconnected local networks consisting of many hundreds of devices that are installed in multiple buildings and locations.