A Maya ambient light combines both an ambient light and a diffuse light. The diffuse portion has a source location and a uniform spherical distribution, while the ambient portion appears to come from everywhere, and is often used as a fast approximation of indirect lighting. Ambient light is typically used to control the overall brightness and color of a scene.
Use an ambient light to simulate a combination of direct light (for example, a lamp) and indirect light (lamp light reflected off the walls of a room).
See light source.