Old style incandescent lights are pretty simple: a wire with electricity going through it. The wire heats up and emits energy as both heat and light. Unfortunately, these bulbs aren't very energy efficient, producing more heat than light. This type of light is the heat source in an Easy Bake oven.
Florescent bulbs conduct electricity across a gas filled chamber, causing the gas to emit energy. That energy then causes a powder on the inside of the chamber to light up. This is much more efficient than incandescent lighting, but only recently has the technology been used to create bulbs that would fit Edison style sockets, which represent the vast majority of the “installed” lighting base. The biggest problem with these florescent bulbs, however, is their disposal, since the gas and powder inside can be dangerous. That said, the bulbs last much longer than their predecessor.