What is a collision domain?

A collision domain refers specifically to a network segment where data packets from multiple devices can collide when they are transmitted simultaneously. In shared network environments, like those using hubs or repeaters, if two devices try to send data at the same time, their packets can interfere with each other, leading to collisions. This results in the need for the packets to be resent after a collision is detected, reducing overall network efficiency.

The concept of collision domains is particularly pertinent in Ethernet networks using CSMA/CD (Carrier Sense Multiple Access with Collision Detection). In such networks, all devices on the same segment hear the traffic, and if two devices transmit simultaneously, the signals collide. This is why network design often involves segmenting collision domains to improve performance, typically using switches which create separate collision domains for each connected device.

In contrast, the other options describe different networking concepts or contexts that do not accurately represent the definition of a collision domain.