A compact fluorescent light (or CFL) is a fluorescent lamp that is increasingly aimed at replacing traditional incandescent lamps (tungsten lighting) as compact arrest and lights are generally agrees to use one 5th to 1/3 the electric power and last 8 to 15 times longer than traditional tungsten lighting. A fluorescent lamp is a gas discharge lamp whereby light is created by the passing of an electrical signal through a usually mercury vapour. This electric field excites the Mercury atoms to produce shortwave ultraviolet light which then causes a phosphor to fluoresce producing what we recognise as visible light.

Fluorescence is the way in which light is emitted by substance due to the way in which that substance has absorbed either light or other forms of electromagnetic radiation. High Street neon lights are an example of fluorescent lights. See compact fluorescent lighting.

In lighting theory, the ‘set light’ (aka background light) is the light used in a traditional lighting setup to illuminate the background or studio ‘set’ to give an audience a clearer picture of the location of the film composition as well as creating additional debt and separation from the subject or person in the foreground.

The concept of set light should not be confused with that of ‘working light’ which is simply like used on location to assist cast and crew in day-to-day activity on the set, working light is not used or seen in the final composition. in some circumstances working light may refer also to available light in a given filming location, for example daylight entering through a window.

Motivated light is an artificial light source that creates an effect that is seen within the frame, but which is understood and believed by the audience to be caused or 'motivated' by an unseen or indeed visible 'real world' light source (and not the technical light source used by the lighting director or cinematographer)

Lighting practicals are a collective term for any single or number of lights that can seen by an audience within shot and which (usually but not always) originate light that is used in the final scene. Examples of lighting practicals include bed side table lamps, candles, desk lamps, torches (flash lights) and indeed any form of lighting where it is evidence to the audience that the light might naturally be expected to come from such light sources.