Sunlight, whether it is simply used to illuminate an exterior scene or when it enters an interior space, provides for interesting and potentially dramatic lighting effects. 3ds Max Desig, has specific tools to simulate its effects.
Light is a very interesting phenomenon. We see it every day, it surrounds us, interacts with us, and yet we understand very little about it, as its physical properties rely on complex formulas. As an artist, you need to understand the subtleties of light without delving too deeply into its complex nature. The key to that effect is to study light around you, understand how it is affecting its surroundings, and try to emulate that in different 3D environments.