Tail lights, also called rear lights or rear lamp, are crucial components of a vehicle.
Tail lights consist of lens and frames called the tail lamp bezel or tail light frame. They are mounted on the rear fender, thus they are also called rear lamps.
Tail lights provide nighttime vehicle conspicuity to the rear. Tail lights are required to produce only red light, and to be wired
such that they are lit whenever the front position lamps are illuminated—including when the headlights are on.
Tail lights may be combined with the vehicles brake lights, or separate from them.
In combined-function installations, the lamps produce brighter red light for the brake lamp function, and dimmer red light for the rear position lamp function.
Regulations worldwide stipulate minimum intensity ratios between the bright (brake) and dim (tail) modes,
so that a vehicle displaying rear position lamps will not be mistakenly interpreted as showing brake lamps, and vice versa.
Light sources for tail lights include color bulbs, LED bulbs, and clear bulbs.