What are xenon headlights?
Despite the name, these aren’t actually ‘xenon lights’. Technically, they’re metal-halide lamps that also contain xenon gas. When you turn them on, they take a little while to reach full brightness, and the xenon shortens that time by giving a minimum light straight away. You may also read about bi-xenon lights, but the only difference between those and plain xenon lights, is that bi-xenons use xenon lights for both full and dipped beam.