A complete lighting unit consisting of a lamp (or lamps), ballast (or ballasts) as required together with the parts designed to distribute the light, position and protect the lamps and connect them to the power supply. A luminaire is often referred to as a fixture.

The luminaire: An individual lighting assembly including the lamp and any housings, reflectors, globes, lenses, shields or other components designed to block or distribute light. For the purposes of this ordinance, an internally illuminated sign is not considered a luminaire

The lamp: as the source of light being emitted from a luminaire, such as a bulb or LED.

Their relationship is inseparable parts for lighting unit, in the help from necessary accessories, such as transformers, ballast, starters or etc.