The second most important setting to define your Material.
The most commonly used setting. It will reflect light in the standard way.
This will reflect no light at all. BaseColor will always be black. This often used for VFX or Light Functions.
This is a fast rendering simulation of SubSurface effects. This shading model works best on objects with a dynamic shadow as it changes the shadowing of the object. Lastly, you can use it on a static object with baked lighting, but the effect will get lost. Best used for character skin or foliage.