A black body is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. The name “black body” refers to its ability to absorb all colours of light. A black body also emits black-body radiation. In contrast, a white body is one with a "rough surface that reflects all incident rays completely and uniformly in all directions.

The beam angle is the term used to describe the lighting distribution in 360 degrees of a certain light fixture. The beam angle of a light source is the angle measured between the central axis of the source to the boundary where the lighting intensity decreases to 50%.

A beam spread is a definition used to describe the lighting distribution of a certain light source or fixture as it hits a surface.

Backlight or backlighting is a method of creative lighting where the light source is behind the object.

There are two main cases:

the illuminated object is a translucent panel that becomes an emitting surface

the illuminated object is opaque and the outlines of the objects standing in front of it are emphasised

Bounced light or reflected light is light that reflects off a surface. The bounced light also reflects the colour of that surface back into the environment.

Brilliance is the effect of lighting on a glossy surface, for example a sparkle from a chandelier, and is produced by the reflection of the light source. A “Play of brilliants” is one of the three layers coined by Richard Kelly, a pioneer of architectural lighting design, that make up good lighting design.