Regardless of the type of headlight, they light your path of travel and allow others to see where you are. There is a fundamental difference between the types of headlights is the technology behind them. For example, the incandescent headlight is really nothing more than an oversized version of the everyday light bulbs we see around the house, just designed for use in cars. The xenon and halogen type of bulbs use a different type of technology, while fog lights, driving lights, and pencil beams all use other types.
- Fog lights. This style of headlight is not found on every car or truck. They are designed so that their light is angled downward sharply towards the road, so that the light they produce is not bounced back by rain, snow, or fog into the eyes of the driver.
- Incandescent. The incandescent headlight is basically an oversized light bulb that you might find around the house. The basic materials are the same, just stronger. Its name derives from how the filament, the little wire inside the bulb, becomes "incandescent" (i.e. it glows) due to the heat generated by the electrical current running through it.
- Xenon. The primary difference between a xenon headlight, or bulb, and an incandescent is that it is filled with a gas (xenon, hence the name) that helps produce a whiter light. The whiter a car's light, the brighter everything appears before the driver and with a xenon headlight, a car can produce a whiter light using less battery power. When a car has less electricity running through the headlights, there is a longer life for those lights as well as for the battery.
- Halogen. This light is the precursor to the xenon headlight and performs in much the same manner.
- Pencil beams. This style of headlight is primarily designed to provide a long range visual effect for the driver. Your standard "driving light" is only designed to give you a visual range of about 1000 feet ahead of you as you are driving. The pencil beam style effectively doubles that to about 2000 feet. However, due to the increased level of light that these headlights put out, many states have laws that deem them to be a hazard to other drivers. Before utilizing them, check to make sure that you are not in one of those states.
- Driving lights. Standard driving lights are designed to give a driver a forward visual range of about 1000 feet, with around 30 degrees of peripheral light.