Headlights/Headlamps are lights in the front of a vehicle which are designed to illuminate the road ahead. They are usually off-white with a hint of orange or yellow, but some high-grade lights have a tint of blue or purple. It is possible to get different colors, but they are usually not street legal because they could be mistaken for emergency lights, or taillights when red. Headlights often become a focus in the styling of a vehicle, since they are generally chrome/reflective and usually sit within the fender area of the vehicle. Not all lights in the front of the car are headlights, however. Fog lamps and turn signals are often found in the front of the vehicle, and are used for different purposes.
Some headlights are hidden when not in use, and "pop up" when they are activated. This design was popular for a time when it had its advantages, but lost popularity when they became notorious for breaking as the vehicle aged. As technology improved, there was also little advantage to having headlights that could be hidden.
A popular aesthetic modification for vehicles is a set of aftermarket headlights, which have many varieties and options. There are a number of street legal and non-street legal colors available (differs geographically), as well as lens tinting, bulb/projector types, and even fixed replacements for pop-up headlights. Many of the shades available for aftermarket lights are tints of blue.
Some racing vehicles don't have headlights, but in order to appear like the original model, decals with the appearance of headlights are applied. Some fake headlights are just a solid color in the area where the real lights would be. NASCAR stock cars are examples of vehicles with decal lights.
Partially Fake Headlights
Some performance automobile headlights are partially fake; a light is placed in the area, and the rest is part of the body but use a solid color or decal to make it appear like the full headlight.
Most people don't need their headlights on all the time, and vehicles equipped with high beams need to be able to allow the driver to switch between settings. Some older cars have the lights wired directly from the battery, to the switch, to the light, and back to the battery to complete the circuit. However, modern cars use relays to reduce production costs, as well as allow for automatic light functions controlled by the on-board computer.
Some vehicles have light sensors which automatically turn on headlights when the sensor doesn't detect much light.
An uncommon feature found in some modern vehicles are headlights that turn slightly to aim down the road ahead when the driver is making a sharp enough turn. They are computer-controlled, because a basic mechanical design would have them constantly moving as the driver makes small adjustments to the steering wheel.