In addition to Tom, Marc and Tony's replies, how about these descriptions:
Discharge Lighting...
Lighting from Lamps which do not use Resistance Elements (AKA Fillaments) to DIRECTLY produce Light output, via emissions from the filament only - as with Incandescent Lamps
(Incandescents are mostly a heat / Infrared Light Generator, with White Light being a "Byproduct").
Or:
Lighting produced via a Plasma contained within an arc tube, with Light output produced from Photons emitted from inert materials in the arc tube, due to a controlled level of current knocking the Photons loose from the inert materials, while the current flows from one Cathode, through the arc tube, and collects in the other Cathode.
Or:
Lighting from Lamps having "Negative Resistance" Characteristics, as opposed to Lamps with a "Linear Resistance" Characteristic - as would be found in Resistance (Filimant) type Lamps - AKA Incandescent Lamps.
Or: (last one)
Lamps which require the Current to be "Ballasted" (automatically regulated) by an external or separate device, in order to operate correctly (and not self destruct instantly); as opposed to Filament Lamps, which do not normally require the Current to be "Ballasted" - due to the Linear Resistance of the Filament.
I have more, but these are boring enough!
Scott
