What most people usually call bulbs or globes are known in the lighting industry as Light Sources or lamps. The original lamps were the Edison Bulbs, which are now available in LED, reviving the vintage look in an energy efficient LED. Today, most types of older technology lamps are being phased out and replace by LED. Some are still available though. Below are common types of lamps.
Arc Lamp: Also called a discharge lamp, or an arc discharge lamp, this is a light
source containing an arc.
Compact Fluorescent (CFL): As the name indicates this is a smaller or more compact version of fluorescent tube. They come with both screw-in and pin-bases and are available in a wide range of light temperatures and sizes. They used
significantly less energy than incandescent lamps.
Electrodeless Lamps: Light sources where the discharge occurs in a chamber with no electrodes (no metal.) The energy for the discharge is supplied by radio
frequency excitation, e.g., microwaves.
Eliptical Reflector Lamp (ER): An incandescent lamp with a built-in elliptically shaped reflecting surface. This shape produces a focal point directly in front of the lamp which reduces the light absorption in some types of luminaires. It is
particularly effective at increasing the efficacy of baffled downlights.
Fluorescent: A high efficiency lamp utilizing an electric discharge through low
pressure mercury vapor to produce ultraviolet (UV) energy. The UV
excites phosphor materials applied as a thin layer on the inside of a
glass tube which makes up the structure of the lamp. The phosphors
transform the UV to visible light.
Halogen: Also called tungsten halogen, is an incandescent lamp containing
halogen gases such as iodine or bromine, which increase the efficacy
of the lamp versus a standard incandescent lamp. They are more
energy efficient than standard incandescent and can last 2-6 times
High Intensity Discharge Lamps (HID): A type of electrical gas-discharge lamp which produces light by means of an electric arc between tungsten electrodes housed inside a translucent fused quartz or fused alumina arc tube which is filled with gas and metal salts. There are various types of HID lamps including
Mercury-vapor, Metal-halide, ceramic MH, Sodium-vapor and Xenon.
This is the standard light bulb that Thomas Edison invented in 1879.
It is also referred to as an A-Lamp. The technology behind them has
changed little. They use a lot of energy, of which only about 10% is used
for light. The rest is emitted as heat.
Light Emitting Diode (LED): Also referred to as Solid State Lighting, LEDs emit light through the movement of electrons in a semiconductor material. LEDs emit light through electron movement in semiconductor material. Because there
is a no filament to burn out, LEDs can last from 10-20 years. They are
also four times more efficient than incandescent lamps and contain no
mercury (as in compact fluorescents).