The physical layout of computers on a network is called a topology. There are three primary topologies: bus, star, and ring. There are variations on these basic topologies, including the star bus and star wired rings.

The bus is the simplest and most commonly used topology (according to book, not IRL). It is a linear configuration, with all computers connected by a single cable. On a bus, signals are sent to all of the computers on the network. To keep the signal from bouncing back and forth along the cable, a terminator is placed at the end of the cable. Only on computer can send data at a time. Therefore, the more computers on a bus, the slower the data transmission speed will be.

In a star topology each computer is directly connected to a central component called a hub. If the central component fails, the entire network goes down.

A Token Ting network connects computers in a logical circle. The signal, or token, passes around the ring through each computer in a clockwise direction. A computr takes the free token and sends data on the network. The recieving computer copies the data and marks it as having been recieved. Finally, the data continues around the ring back to the sending computer, which removes the data from the ring and releases a free token.

A hub is used to centralize LAN traffic through a single connection point. If a cable breaks on a network that uses a hub, the break will only affect that segment and not affect the rest of the network. Networks can be expanded easily using hubs; they allow for use of different types of cabling.