Carrier-Sense Multiple Access/Collision Avoidance (CSMA/CA)
Multiple Access (MA)
Unlike a deterministic method of network access (for example,the method used by Token Ring), all Ethernet devices simultaneously have access to an Ethernet segment.
Collision Avoidance (CA)
A complex schedule tries to ensure that two or more participants do not start a transmission at the same time to avoid collisions. If overlapping does occur, this will be detected and the transmission will be tried again. Common is wireless networks and was crated to help with the scalability limitations of CSMA/CD.
Carrier-Sense (CS)
A device attached to an Ethernet network can listen to the wire, prior to transmitting, to make sure that a frame is not being transmitted on the network segment.