CAN stands for Controller Area Network and is a bus often used in automotive applications. It is a two-wire differential protocol and works on baud rates from 10 kbits/sec to 1 Mbits/sec.
The CAN bus is a serial bus. It allows multiple masters and uses a broadcast model. A message start with an ID, can contain up to eight data bytes and uses non-return-to-zero encoding. Each node can receive, but only one can send at each point in time. It uses CSMA/CA algorithm for bus access. The lower the (numerical) ID, the higher the priority. Short networks (below 40 m) can achieve bit rates up to 1 Mbit/s.