Halogen bulbs are actually an advanced variation of incandescent bulb technology. One of the major factors that shorten an incandescent bulb's lifespan is the evaporation of the tungsten within the bulb. By adding a trace amount of a halogen gas (methyl bromide) inside the bulb, a chemical reaction removes the tungsten from the wall of the glass and deposits it back onto the filament, extending the life of the bulb. The higher temperatures of halogen lighting contribute to a whiter light, a higher light output and a greater efficiency.