Computer networks are classified by five main types and may be visualized as the objects for which the types are named: bus, ring, star, tree and mesh. The pattern of device connections relative to the network's server or router is called network topology, and visualizing topology as a familiar object helps users understand and remember a network's function. Networks may be single types or combinations.
Star topology consists of a central hub with devices connected to it independently, like star points. Ring topology connects all devices in a ring. Bus topology connects all devices in a line with a single backbone. Tree topology connects multiple star topologies to a bus, which can be visualized as the tree's trunk. Mesh topology connects devices to a hub but also may connect devices to each other and may have standalone devices connected only to the hub.
Network diagrams show how the network is connected and how data is routed through the system but are not necessarily representative of the physical location of network hardware. For instance, a star topology may represent a network of devices physically arrayed around a central server but could also represent a centralized network with tangential devices on several floors of a building.