What happens when light strikes the surface of a material?

When light strikes a surface there are two things that can happen: (i) the change in refractive index can cause light to be reflected by the surface and this surface-reflected light is called specular reflection; (ii) light that is not reflected at the surface can penetrate the body of the material although as it passes through the surface the change in refractive index slows down the speed of light and this causes the light to be refracted.

Light may pass completely through a material, in which case we say that it has been transmitted. Alternatively the light may be absorbed by the material or it may be scattered. Light that is scattered or reflected may eventually pass out of the front, back, or side of the material.