A network is a connection among homogeneous as well as heterogeneous computer systems. Over the years, several types of networks have been developed for various purposes and overcoming limitations of other networks. Each type of network has its utility in certain scenarios and has drawbacks in others. To understand which network is most suitable for the task at hand, it is essential to have a method to distinguish the types of networks. One way of classifying different types of networks is on the basis of size. In a broad sense, size can be determined by the geographical coverage of a network. Types of networks depending on the geographical areas they encompass are listed below:
- PAN: Personal Area Network - This is a very short range network, used mostly for creating a network of self - used devices, like connecting your personal computer to your home printer and other personal devices.
- LAN: Local Area Network - This is another short range network, which is larger than your PAN, but it is limited in its area coverage. A LAN typically comprises of a network created in a single building or campus. For example, several offices have a LAN to ensure connectivity of all office computers among themselves and with shared peripherals such as printers etc. Sometimes, the term CAN, for Campus Area Network is used to denote a network comprising of nodes belonging to a single campus.
- MAN: Metropolitan Area Network - As the name suggests, a MAN encompasses an entire metropolitan region, like a city or town. An example is the cable network of TVs in most cities.
- WAN: Wide Area Network - Wide area networks cover regions beyond cities, even connecting subcontinents. The Internet is the world's largest WAN.
Another classification of networks is on the basis of their purpose. As such, networks can be classified as :
- VPN: Virtual Private Network - A VPN is used to provide end-to-end connection with security over a network. A VPN is built of virtual circuits and topologies over already existing physical connections.
- EPN: Enterprise Private Network - An enterprise network is a network built for an enterprise, comprising of nodes in office building, remote locations, offsites etc.
- SAN: Storage Area Network - A SAN connects data stores with servers. Often, large amounts of data will be stored in a number of locations. A server requesting retrieval of data can utilize SAN networks to manage distributed data access.