For years, components of networks have included such activities as listening to the radio, watching a favorite program on television, traveling by vehicle, and talking on the telephone. Just as national broadcasting companies have made use of the facilities of many local broadcasting stations to bring viewers their favorite radio or television show, telephone companies have used wires, microwave stations, and satellites to help individuals communicate with family and friends. The roadway and highways of cities, counties, and states, make up another familiar network common to vehicle travelers. Similar to the networks referred to above is another group of networks classified as telecommunications networks. Telecommunications networks are those networks made up of electronic devices, such as interrelated groups of computers linked by some form of communication channel.
Topology refers to the configuration or the different ways stations or nodes are connected.
In the star topology, a central computer serves as the hub in the middle of the star configuration. For communication to pass from one station or node on the exterior of the star to another, it must pass through the computer or processor serving as the hub. As the hub manages the flow of communications, it is easy to detect failure of a particular station. The network will continue to process information even if one station or node fails. However, if the computer serving as the hub for the network fails, the whole network fails.