CAN bus, function

Bus: 

The term "bus" is used to describe a system for conveyance and distribution of data.

CAN: 

Control Area Network (CAN) is a bus system which functions using two wires. These are referred to as "bus lines". The data is transferred serially, i.e., in succeeding order, to the control modules connected via the bus lines.

These control modules communicate by means of the CAN bus, i.e., they exchange data using the CAN bus.

The two data-bus wires are twisted around one another in order to prevent electromagnetic interference and interference-radiation emissions. The spacing of the twisted elements is important.