Each fixture type has default rendering settings that work well by default. There are many cases where a user may want to override these settings for best performance and visual target.
These are divided into sections called "Light", "Beam" and "Emissive" Settings.
Light- this is the light footprint, as cast by the fixture and strikes a surface.
Beam- this is the "volumetric" contribution of a light as it strikes small particles in the air.
Emissive- this is the glow of the face of the area where the light exits a fixture