Jason Dion's Network+ Course Practice Test

In a bus topology, all devices connect to a single coaxial cable that carries signals to everyone on the network. That means the transmission medium is shared, so multiple devices can listen to what’s on the line. Because many devices can hear the same signal, access must be coordinated to avoid collisions— Ethernet uses CSMA/CD to manage when a device can transmit and to detect if two devices transmit at once. You also typically have terminators at each end of the cable to prevent signal reflections.

This setup contrasts with other topologies. In a mesh, devices have multiple interconnections, not one shared line for all; in a star, each device has a dedicated link to a central switch or hub; and in a ring, signals travel around a closed loop, often with token passing. None of those configurations rely on a single shared medium that all devices listen to in the same way as a bus.