The Controller Area Network (CAN) is an international standard defined in the ISO 11898. CAN was developed as a solution for networking in distributed real time systems. CAN which is a two-wire, half duplex, high-speed network system is well suited for high speed applications using short messages. It supplies high level security and high data exchange rates. One of the most important features of CAN technology is the guaranteed maximal latency for bus access that makes it the choice for real time systems. The scope of this seminar is to describe the way of working of CAN protocol and its features. Controller Area Networking was carefully designed to suit the needs of a real-time system and it's not a surprise that it gets acceleration in many different industry fields. The ability to work in very difficult conditions and the approved fast exchange of data, in conjunction with the low cost and the easy maintenance, answer exactly the needs of the industry. There are on the market already many development tools for CAN applications. Indeed, it's not a multi-purpose network, because of it's addressing scheme, and since it's limited in the amounts of data that may be included in a single frame, but the purpose of the CAN developers was not to compete with the Ethernet.