Carrier Sense Multiple Access with Collision Detection (CSMA/CD)

In local area networks a method used by computer's access to the communication channel. With CSMA/CD, each component of the network (called a node) has an equal  right to access the communication channel.  If two computers try to access the network at the same time, the network uses a random number to decide which computer gets to use the network first.

This channel access method works well with relatively small to medium sized networks (two or three dozen nodes). Large networks use alternative channel access methods, such as polling and token passing to prevent overloading or locking up the  system.