One of the biggest differences between halogen and fluorescent light bulbs is that halogen bulbs use a tungsten filament to emit light. Fluorescent light bulbs have no filament whatsoever.
Fluorescent light bulbs emit light when an electrical current is drawn between two electrodes. The current reacts to mercury and argon gases that produce photons, which react to the bulb's inner coating and emit light. Halogen light bulbs emit light in the same way as traditional incandescent light bulbs. Electricity heats up the halogen bulb's tungsten filament, which in turn emits light.
According to the California Energy Commission, fluorescent light bulbs are much more energy-efficient than halogen light bulbs. Like incandescent light bulbs, much of the energy drawn in by halogen light bulbs is given off in the form of heat.
Fluorescent light bulbs are rated to last longer than halogen light bulbs. While halogen light bulbs can last two to three times longer than traditional incandescent light bulbs, fluorescent bulbs can last up to 10 times longer than incandescent bulbs.
Fluorescent light bulbs and halogen light bulbs both contain different types of fill gases. Fluorescent light bulbs contain both mercury and argon gases. Halogen light bulbs contain traces of a halogen like iodine.
Fluorescent and halogen light bulbs are used both indoors and outdoors. Fluorescents are energy-efficient and work well outdoors because of the long hours they will be used. Because turning a fluorescent light bulb on and off too often can dramatically decrease its life, manufacturers recommend that fluorescent light bulbs be used in situations where they will stay on for extended periods of time. Halogen light bulbs are often used as headlights in automobiles. PopularMechanics.com recommends that halogen lights not be used in children's rooms, play areas and older houses because they run rather hot.