Headlights are not only used at night but also in harsh weather conditions. Daylight could easily well be deflected by precipitation. Headlights are mounted on the front of your car, to light the road ahead of you. They have reflectors and special lenses. A headlight is usually the sealed beam construction type. This means that the filament, reflector and lens are fused together into an airtight unit. Installation and removal are easily accomplished because of prongs that fit into a wiring socket.