Computer networks come in different sizes. Each network is a cluster of network elements and their sources. The size of the cluster determines the network type. There are, in general, two main network types: the local area network (LAN) and wide area network (WAN).
Local Area Networks (LANs):
A computer network with two or more computers or clusters of network and their sources connected by a communication medium sharing communication protocols and limited in a small geographical area, such as a building floor, a building, or a few nearby buildings, is termed a local area network (LAN).
The advantage of a LAN is that all network components are close together so the communication links keep a higher speed of data transfer. Also, because of the closeness of the communicating components, high-cost and high-quality communicating elements can be used to deliver better service and high reliability.
Wide Area Networks (WANs):
A wide area network (WAN), on the other hand, is a network made up of one or more clusters of network components and their resources, but instead of being limited to a small area, the components of the clusters or the clusters themselves are spread over a wide geographical area as in a region of a country or across the whole country, several countries, or the whole globe like the Internet.
Some advantages of a WAN involve sharing services to a wider community and availability of a wide array of both hardware and software resources that may not be available in a LAN. However, because of the wide geographical areas covered by WANs, communication media are slow and often unreliable.