Lighting is an option for Graphics3D and related functions that specifies whether to use simulated illumination in three-dimensional pictures.
True uses simulated illumination. The ambient light level is specified by the option AmbientLight. The option LightSources gives the positions and intensities of point light sources.
False uses no simulated illumination. In SurfaceGraphics, polygons are then shaded according to their height, or according to the ColorFunction option that is given.
See the Mathematica book: Section 1.9.7, Section 1.9.7, Section 2.9.9, Section 2.9.12.
See also: Shading, ColorFunction, SurfaceColor.
The first plot uses the default setting (True) for Lighting; the second turns the lighting off and uses a color function.
Evaluate the cells to compare the graphics.