The lighting system of a automobiles consists of lighting and signaling devices mounted or integrated to the front, sides and rear of the vehicle. The purpose of this system is to provide illumination by which for the driver to operate the vehicle safely after dark, to increase the visibility of the vehicle, and to display information about the vehicle's presence, position, size, direction of travel and intended travel, and braking status. Other lighting used are driving lights, fog lamps, and cornering lamps.

"Driving lamp" is a term deriving from the early days of nighttime driving, when it was relatively rare to encounter an opposing vehicle. Only on those rare occasions when one did briefly face opposing traffic would one use the dimmed or "passing beam". The full or "bright" beam was therefore known as the driving beam, and this terminology is still found common usage, which do not distinguish between a vehicle's primary (mandatory) and auxiliary (optional) upper/driving beam lamps. The "driving beam" term has been supplanted in the US by the functionally descriptive term auxiliary high-beam lamp. They are most notably fitted on rallying cars, and are occasionally fitted to production vehicles derived from or imitating such cars. They are common in countries with large stretches of unlit roads.

Fog lamps provide a wide, bar-shaped beam of light with a sharp cutoff at the top, and are generally aimed and mounted low on the car. Lamps may be either white or yellow. They are intended for use at lower speeds to increase the illumination directed towards the road surface and verges in conditions of poor visibility due to fog, rain, snow or dust. As such, they are often most effectively used in place of dipped-beam headlamps, reducing the glare back from fog or falling snow.

The respective purposes of front fog lamps and driving lamps are often confused, due in part to persistent misapprehension by the public at large that fog lamps are necessarily yellow, while any auxiliary lamp that makes white light is a driving lamp. Auto makers and aftermarket parts and accessories suppliers frequently refer interchangeably and incorrectly to "fog lamps" and "driving lamps". In most countries, weather conditions necessitating their use are very rare, and there is no legal requirement for them, so their primary purpose is frequently cosmetic.

Cornering lamps are available on some models in North America; white cornering lamps provide extra lateral illumination in the direction of a turn or lane change. These are actuated in conjunction with the turn signals, though they burn steadily, and they may also be wired to illuminate when the vehicle is shifted into reverser. US technical standards contain provisions for front cornering lamps as well as for rear cornering lamps.