Laws of reflection:

Reflection of light : when ray of light strikes the boundary of two media such as air or glass, a part of light turned back into the same material . This phenomenon is known as "reflection of light". 

There are two types  of reflection : 

1. Regular reflection:  When the reflection takes place from a perfect plane surface it is called Regular Reflection. In this case, the reflected light has large intensity in one direction and negligibly small intensity in other directions.
2. Diffused reflection: When light is reflected from a irregular surface  we do not get a regular behavior of
   light. Light  reflects from the  surface such that a ray incident on the surface is scattered at many angles rather than at just one angle.

 It has been found that rays undergoing reflection follow two laws called the Laws of Reflection:
(i) The incident ray, the reflected ray, and the normal at the point of incidence lie in the same plane. The plane is called the
plane of incidence (or plane of reflection).     

(ii) The angle of incidence (the angle between normal and the incident ray) and the angle of reflection (the angle between
the reflected ray and the normal) are equal, i.e.,
                                                                                  $\angle i=\angle r$

 Normal Incidence: When a ray incident normally on a plane $\begin{aligned} & i=r=0 \\ & \delta=180^{\circ}\end{aligned}$

             
Grazing Incidence: In case light strikes the reflecting surface tangentially