The lighting system of a motor vehicle consists of lighting and signalling devices mounted or integrated to the front, sides, rear, and in some cases the top of the motor vehicle. The purpose of this system is to provide illumination for the driver to operate the vehicle safely after dark, to increase the conspicuity of the vehicle, and to display information about the vehicle's presence, position, size, direction of travel, and driver's intentions regarding direction and speed of travel.

The colour of light emitted by vehicle lights is largely standardised by longstanding convention, first codified in the 1949 Vienna Convention on Road Traffic and later specified in the 1968 United Nations Convention on Road Traffic. Generally, but with some regional exceptions, lamps facing rearward must emit red light, lamps facing sideward and all turn signals must emit amber light, lamps facing frontward must emit white or selective yellow light, and no other colours are permitted except on emergency vehicles.

Dipped-beam (also called low, passing, or meeting beam) headlamps provide a light distribution to give adequate forward and lateral illumination without blinding other road users with excessive glare. This beam is specified for use whenever other vehicles are present ahead. The international ECE Regulations for headlamps specify a beam with a sharp, asymmetric cutoff preventing significant amounts of light from being cast into the eyes of drivers of preceding or oncoming cars. Control of glare is less strict in the North American Society of Automotive Engineers (SAE) beam standard contained in FMVSS / CMVSS 108.