What function do headlights have on cars?

The main function of headlights on cars is to illuminate the roadway for drivers, though different types of lights serve additional purposes. Halogen, auxiliary, pencil beam, xenon, incandescent, fog and driving are all different types of auto headlights, according to Auto Media.

Halogen lights give off a bright, white-colored light and last longer than other types of bulbs. Auxiliary lights provide a stylized aspect to a vehicle, while allowing drivers to see more clearly at night. Pencil beam headlights allow drivers to see up to 2,000 feet in front of the vehicle. Xenon lights produce a notable white light and require minimal drain on a vehicle's battery, according to Auto Media.