The configuration of of cables, computers, and other devices in a local area network (LAN) or other communication systems. There are four main types of topologies used:Bus topology- All devices are connected to a central cable, called the bus or the backbone. This topology is inexpensive and primarily used by ethernet systems.Ring topology- All devices are connected to each other so that every device is directly connected to two others. This type is difficult to install and expensive but provides a high bandwidth and spans larger distances.