Media Access Control (MAC) is the lower sublayer of the OSI data link layer, the interface between a node's Logical Link Control and the network's physical layer. The MAC differs for various physical media.
The MAC sublayer is primarily concerned with breaking data up into data frames, transmitting the frames sequentially, processing the acknowledgment frames sent back by the receiver, handling address recognition, and controlling access to the medium.
See also: MAC address, Ethernet, token ring
This article was originally based on material from FOLDOC, used with permission.