Carrier sense multiple access with collision avoidance

In computer networking, Carrier Sense Multiple Access With Collision Avoidance (CSMA/CA) is a medium access control (MAC) protocol in which:
•a carrier sensing scheme is used,
•a data station that intends to transmit sends a jam signal
•after waiting a sufficient time for all stations to receive the jam signal, the data station transmits a frame
•while transmitting, if the data station detects a jam signal from another station, it stops transmitting for a random time and then tries again.
CSMA/CA is a modification of pure Carrier Sense Multiple Access (CSMA). Collision avoidance is used to improve the performance of CSMA by attempting to reserve the network for a single transmitter. This is the function of the "jamming signal" in CSMA/CA.
Token Passing is a technique in which only the system which has the token can communicate. The token is a sort of control mechanism which gives authority to the system to communicate or use the resources of that network. Once the communication is over, the token is passed to the next candidate in a sequential manner.

Ethernet is popular because it strikes a good balance between speed, cost and ease of installation. These benefits, combined with wide acceptance in the computer marketplace and the ability to support virtually all popular network protocols, make Ethernet an ideal networking technology for most computer users today.