Track lighting is a method of lighting where light fixtures are attached anywhere on a continuous track device which contains electrical conductors. This is in contrast to directly routing electrical wiring to individual light positions. Tracks can either be mounted to ceilings or walls, lengthwise down beams, or crosswise across rafters or joists. They can also be hung with rods from especially high places like vaulted ceilings.
Typical systems have line voltage running through a recessed track. The track may have more than one live conductor, so that multiple switched circuits can be used to control different fittings on the same track. Installers will place the tab of the connector on the fixture to one side or the other when attaching it to the track.