A light fitting performs a number of functions. It enables the electrical connection to the lamp itself, it protects the lamp, and it protects the lamp, and it directs or diffuses the light from the lamp. In an indoor situation the most important aspect of a fitting is the way in which it controls the flow of light. While fittings can be broadly divided into downlighters, uplighters, spotlights, ceiling-mounted, suspended and recessed fittings, many sophisticated modern fittings can be used in alternative positions, and combine qualities from other types, just as many lamps are configured in ways that in themselves direct the flow of light. A recessed fitting can also be a spotlight, for example, and indeed a downlighter can be recessed into a floor as easily as into a ceiling. (The main consideration here is whether the lamp itself will only operate in specific burning position, together with the question of heat diffusion around the fitting, and the provision of a safety glass.)
In many cases the fitting can be used with an alternative range of lamps; for example, a standard spotlight fitting will often accommodate lamps with different beam widths where the work of controlling the flow of the light is done by the lamp itself. Additional features available for fittings include diffusers, often used over fluorescent lamps, slots on recessed fittings, and plain or tinted glass rings to achieve an alternative diffusion of light from a recessed fitting.