Shader Family: Surface Material
Causes illuminated objects to react to light, but only their surface shading is computed. Illuminated surfaces will be rendered with diffuse and ambient color, but non-illuminated surfaces will return only ambient light. No reflection, transparency, or refraction is computed.
This illumination shader can be used almost anywhere in a render tree, just like a surface shader. The illumination nodes are faster and take less memory since they don't calculate any reflections, refractions, or transparencies. You can use any number or combination of illumination and surface shaders to control various parts of your effect. Illumination shaders are often mixed (as the Base Color using a mixer shader) with textures to add realism to them. Also, you can use textures to control color inputs (such as Diffuse or Ambient).