Incident ray: The ray of light that falls on the reflecting surface is called incident ray. 

Reflected ray: The ray that bounces back from the reflecting surface, after reflection from it is called reflected ray. 

Point of incidence: The point at which the incident ray strikes the reflecting surface is called point of incidence.

Normal: The line which is drawn perpendicular to the reflecting surface, at the point of incidence is called the normal at that point. 

Angle of incidence: It is the angle between the incident ray and the normal to the reflecting surface at the point of incidence. It is denoted reflection by i. 

Angle of reflection: It is the angle between the reflected ray and the normal to the reflecting surface at the point of incidence. It is denoted by r.