Topologies is the manner in which your Computer systems/servers are connected.

There are different types of topologies like :

1. Bus Topology 

2. Mesh Topology

3. Ring Topology

4. Tree topology

5. Star topology etc.

In Bus Topology, computers are arranged in a form of a bus and data communication takes place in a unidirectional way. 

In mesh topology, all the computes are connected to each other and alot of wire is used. If one system fails the other systems still keep on going.

In Ring topology, the systems are connected to each other in other in a form of Ring. It is one directional. But if we connect one more ring it becomes bi directional in opposite direction. 

In Tree topology, systems are connected in a hybrid manner. Every child node has a parent node and there is a Root node in the whole arrangement.

In Star topology, there is a Central HUB to which all the other systems are connected.