A ring network is a network topology where each node is connected to two other nodes, so as to create a ring. Ring networks tend to be inefficient when compared to Star networks because data must travel through more points before reaching its destination.
For example, if a given ring network has eight computers on it, to get from computer one to computer four, data must travel from computer one, through computers two and three, and to its destination at computer four. It could also go from computer one through eight, seven, six, and five until reaching four, but this method is slower because it travels through more computers. Ring networks also carry the disadvantage that if one of the nodes in the network breaks down then the entire network will break down with it as it requires a full circle in order to function.
The token ring network is a ring topology only at the logical level, it runs on a physical Star network, using central devices called MSAUs or MAUs.
Advantages
Data is quickly transferred without a bottleneck. The transmission of data is relatively simple as packets travel in one direction only. Adding additional nodes has very little impact on bandwidth. It prevents network collisions because of the media access method or architecture required.
Disadvantages
Data packets must pass through every computer between the sender and recipient. If any node fails then the ring is broken and data cannot be transmitted successfully. It is difficult to troubleshoot the ring. Because all stations are wired together, to add a station you must shut down the network temporarily.