The wire harness used in a product, in general and as usual, is a set consisting of wires, cables, terminals, sockets and other devices that are responsible for transmitting electric current and information required by electrical and electromechanical operators. In the car wiring harness, depending on the type and performance expected from the wiring harness, usually in addition to the types of wires, cables, terminals and sockets, there are hundreds of other electrical and peripheral parts such as fuses, relays, connectors, protectors, brackets and other auxiliary devices. They are connected to each other and form a wiring harness related to a part of the car.

Connecting different car wiring harnesses to each other with special interconnectors make a set in the form of tree branches, and therefore this set is called a car wiring tree. The main components of a car wiring tree usually include the wiring harness of the engine area, dashboard, roof, floor, doors, bumpers, etc., which enable the operation of a wide range of car operators.