Reflexion and diffusion

When light hits a surface, e.g. a mirror, it is reflected. This phenomenon is called "reflexion". The angle between the incoming ray of light and the lead (in the image: α) as well as the angle between the outgoing ray of light and the lead (in the image: β) are equal.

The laws of reflexion: α = β

Incoming and outgoing rays of light are in one level.