Here is a brief description of the types of bulbs available today.

Incandescent bulbs: Incandescent bulbs are inexpensive and readily available in a variety of wattages and shapes. They produce a yellowish-white light that is emitted in all directions. They are available in either clear or frosted. General (A), Globe (G) Decorative (D),
(flame, teardrop, and other shapes)

Reflective coating inside the bulb directs light forward, giving you better beam control than general service bulbs. Flood types (FL) spread light. Spot types (SP) concentrate the light.

PAR 16, 20, 30 and 38 reflectorized bulbs provide better beam control than regular incandescent PAR bulbs. Available in numerous spot and flood beam spreads. Used in track, recessed, and outdoor spot and floodlights.

T-3 Double Ended bulbs are available in a variety of base types and are used in wall sconces, Torchieres, and outdoor floodlights. The direction of the light is controlled by the fixture.

T-4 Single-Ended bulbs come in both mini-can and bayonet base types and are used in wall sconces, bath bracket, Torchieres, and pendants. The direction of the light is controlled by the fixture.

FLUORESCENT
Use 1/5 to 1/3 as much electricity as incandescents with comparable lumen ratings and last up to 20 times longer. Compact types are used in smaller, trimmer fixtures such as recessed downlights, wall sconces, close-to-ceiling fixtures, and track lights. Screw-in types can be used in place of incandescents in standard lamp sockets. Available in a wide spectrum of colors. Warm white tones best duplicate the color of incandescents.