The differences between halogen and xenon light bulbs include longevity, efficiency, and price. Both types of bulbs are used in automobile lights, although halogens are more common as of 2011.
Halogens are notable for their long life, which averages about 1,000 hours, according to "Battle of the Headlights: Halogen vs. Xenon vs. LED," by AutoEvolution editor Bogdan Popa. The bulb provides a very bright light but becomes very hot, losing a lot of energy in the form of heat.
Xenon bulbs have an even longer life, averaging about 2,000 hours. They also consume less energy. However, they produce a lot of glare and are more expensive. In addition, xenon bulbs may contain toxic materials such as mercury, depending on the manufacturer.
Xenon bulbs are recognisable by the slightly blue light they emit, while halogens produce a bright white light. Halogen bulbs are also reactive, so they can be damaged by skin oil and can explode when they fail, so manufacturers typically use a lens made of heavier glass to protect them.