MAC - Media Access Control
The interface (a stand alone chip or embedded in a
CPU) which
performs the IEEE Ethernet protocol. The
MAC is responsible
for taking Ethernet packets from memory and transmitting them as a
serial stream via the
PHY and receiving the serial stream from the
PHY and converting them into packets in memory.
For more information, check out the
http://en.wikipedia.org/wiki/MAC_address page.
