A computer network is created when data communication/ data transmission channels link several computers and other devices, such as printers and secondary storage devices. The two basic types of networks are local-area networks and wide-area networks.
Each computer or device is a network is called a node. The arrangement by which the nodes are connected is the topology of the network. A network can be arranged in one of four different topologies as follows:
1. Star network
In a star network, several devices connected to one centralized computer. All communications go through the centralized computer, allowing it to control the operations, workload, and resource allocation of the other computers in the network.
2. Ring network
In a ring network, several devices connected to each other in a closed loop by a single communication channel. No computer is centralized in this network. Data must travel around the ring to each station in turn until it arrives at the desired station.
3. Tree network
In a tree network, computers link in a hierarchical fashion and require data to flow through branches. One advantage of a tree structure is that functional groupings can be created. However, data movement through this network can be slow.
4. But network
In a bus network, each computer is connected to a single communication cable via an interface. Every computer can communicate directly with every other computer or with device in the network. This topology is frequently used with local are networks.