a mesh topology is made up of a network where each device has a point-to-point connection to every other device on the network. this provides the dedicated capacity of a point-to-point link ot each device and significant fault tolerance. however, the complexity and cost make this configuration impractical for networks with a large number of devices. also much of the bandwidth available in mesh configuration is wasted. for those reasons, mesh topologies are generally used for interconnecting only the most important sites with multiple links. this is called a hybrid mesh or partial mesh.

most expensive topology of others

look at the picture to see how a mesh topology looks like