With the hybrid topology, two or more topologies are combined to form a complete network. For example, a hybrid topology could be the combination of a star and bus topology. These are also the most common in use.
In a star-bus topology, several star topology networks are linked to a bus connection. In this topology, if a computer fails, it will not affect the rest of the network. However, if the central component, or hub, that attaches all computers in a star, fails, then you have big problems since no computer will be able to communicate.