Light fixtures are the hardware required to hold and operate artificial light sources; the layout of light fixtures is their arrangement in the room.
When complementing day light with artificial light, layout and fixtures can be as important to good lighting as the light source. Good fixture layout and design can distribute light well, separate task lighting from ambient lighting, provide good controllability, and even change the color of the light source.
Successful design of fixtures and layout is measured by the amount of energy required to achieve the right lighting for the space. The less energy required for comfort, the better. Use manufacturers that publish luminous efficacy measurements for certain light sources in certain fixtures, to avoid guessing how fixtures will affect sources.
Types of Luminaire
Luminaires are the fixtures that house lights. They greatly affect both the brightness and the distribution of the light, because they bounce and/or filter the light from their lamps, for different effects. Types of luminaires are generally categorized by their light distribution. Some common distributions are shown below: direct, semi-direct, and direct-indirect.