Kinds of Lights

Incandescent Lights

• In an incandescent lightbulb, a hot wire or filament glows when an electric current passes through it, producing heat and light. General service bulbs -- inexpensive, readily available lightbulbs -- produce a yellowish-white light that shines in all directions. Reflectorized bulbs have a reflective coating meant to direct the light in a single direction. People use general service bulbs for floor lamps, ceiling fan lighting and other common uses. Most incandescent lights last between 1,000 and 2,000 hours.

Fluorescent Lights

• Fluorescent bulbs work by passing an electric arc between cathodes, exciting mercury and other gases to produce radiant energy that converts to visible light through a phosphor coating. These bulbs typically last nearly 20 times longer than incandescent bulbs and require 1/3 as much electricity. Compact fluorescent lights work well in floor lamps and other comparable fixtures. T8 bulbs appear in large ceiling fixtures, especially in commercial lighting.

Halogen Lights

• Halogen bulbs work like standard incandescent bulbs, creating light by transferring electricity through a tungsten filament. Unlike its predecessor, however, halogen bulbs burn brighter and use less electricity for a longer period of time. For this reason, these bulbs generally cost more. Halogen bulbs also burn at very hot temperatures, making them very difficult to touch when lit. Touching these bulbs when lit also transfers surface contaminants that frequently cause hot spots on these bulbs.

LED Lights

• LED lights work when voltage causes negatively charged semiconductors to combine electrons and create photons. As a result, LED bulbs have a long life span, especially in comparison to other types of lighting, and do not reach high temperatures. LED lights also produce less light when used singularly, however, so many people prefer to use these bulbs in low-lighting settings, e.g., as strings of Christmas lights.

High-Intensity Discharge Lights

• HID bulbs work when an arc passes between cathodes in a pressurized tube. This causes the vaporization of metallic additives, creating light. These bulbs have a long life span, shining two to three times longer than halogen lights, and use small amounts of electricity. The bright light produced shines around four times brighter than halogen lights, as well. These bulbs appear most frequently in outdoor security settings and area lighting, but often light up staircases, bookcases and artwork.