How do non-fluorescent light bulbs work?

There are basically three ways electricity is converted into light:

1. A current passing through a wire causes it to get very hot and glow. This is how "old fashioned" incandescent and halogen lights work.

2. A current jumps in between two electrodes, creating an arc. Usually the arc is enclosed in an tube filled with gas that glows when the arc passes electricity through it. IN some lamps, the gas glow is the light source (mercury vapor, HID, sodium). In others, the gas glow causes a fluorescent coating to glow.

3. New technology allows solid-state devices to create light directly. This is how LEDs convert electricity into light.