By definition, a network is a group or is a system that links the components together. A network of retail stores, for example, involves some sort of relationship between the shops. A railway network suggests that the traces are connected to each other at various points. And a computer network that connects computers.
The most popular by far the world's computer network is the Internet. The Internet is, in fact, a collection of smaller networksthat are interconnected together - a network of networks if you can imagine that.
Wireless Network Bridge
But computer networks don't necessarily have to be large or complex. By definition, the smallest possible computer network would include just two interconnected computers. The interconnection can be achieved using a cable or by wireless technology. Whatever the medium, as long as the computers can communicate together they are part of a network.
Surprisingly, the Information Technology industry doesn't define networks by size, rather, by location. Computers that are interconnected in a small geographical location such as a home or an office are said to be in a LAN (Local Area Network). A LAN can have two computers or two thousand computers.
Conversely, computers that are connected across a wide geographical area such as between cities or countries are said to be in a WAN (Wide Area Network). Strictly speaking a WAN actually interconnects LANs. Five computers in a New York office are in a LAN, however, the New York office also connects to an Office in Chicago who hosts ten other computers. All together, that network is said to be a WAN spanning New York to Chicago. But individually each office is a LAN in its own right. One LAN in New York and one LAN in Chicago. This is why we say that strictly speaking a WAN interconnects LANs.
A description of how the network is wired together can be provided using a physical network topology. Network topologies are used to describe the different ways to connect computers together. A bus topology, for example, describes computers connected across a common wire in a linear fashion. A star topology describes computers connected to a common central device such as a switch. Other types of common topologies include ring topology as well as mesh and partial mesh topology.
But possibly the most important working components of a computer network are the protocols. A protocol is a set of rules. In order to communicate correctly, computers must talk the same protocol so that they understand what is being received and know how to send information in return. The IT industry has successfully established TCP/IP as the dominant network protocol across the world. The standardization of TCP/IP in computers has allowed the internet to thrive because is provides a common language that computers can use to communicate with each other.
Easy to Understand Definition of a Computer Networkwireless network bridge