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.
Many types of lamps are used for turn signal, brake lamps, side and clearance marker lamps, and interior lamps. Standardized type numbers are used by manufacturers to identify bulbs with the same specifications. Bases may be bayonet-type with one or two contacts, plastic or glass wedge, or other types such as wire-loop or metal caps used on tubular lamps. Screw-base lamps are never used in automobile applications due to their loosening under vibration. Signal lamps may have clear bulbs, or may be coated red or amber to provide light of the required colours for turn signals and brake lamps.