A computer network is composed of multiple connected computers that communicate over a wired or wireless medium to share data and other resources. For instance, a home computer network may consist of two or more computers that share files and a printer using the network. The size and scalability of any computer network are determined both by the physical medium of communication and by the software controlling the communication (i.e., the protocols).
Computer networks may be classified according to the network layer at which they operate according to some basic reference models that are considered to be standards in the industry such as the seven layer OSI reference model and the four layer Internet Protocol Suite model. In practice, the great majority of networks use the Internet Protocol (IP) as their network layer. Some networks, however, are using IP Version 6 IPv6, usually in coexistence with IPv4. IPv6 use is often experimental. it is an interconnection of a group of computers in other words.
