What is CAN bus and why is it used in vehicles?

Controller Area Network (CAN) is a robust serial communication protocol developed for automotive applications. It uses a two-wire differential signal (CAN-H and CAN-L) for noise immunity, operates at speeds up to 1 Mbps, and uses message-based communication where any node can broadcast. CAN is used because it reduces wiring complexity, provides fault tolerance, enables distributed control, and is an industry standard allowing multi-vendor integration.