It is the bouncing back of a light ray/wave when it hits a shiny, smooth surface. Change in direction of a light ray.
Reflection
He discovered the theory/reflection of light
Thomas Young
This says that the Angle of Incidence is equal to the Angle of Reflection
Law of Reflection
It is a flat reflective surface. We use this in our everyday lives.
Plane Mirror
It is a mirror that bulges inward.
Concave Mirror
It is a mirror that bulges outward.
Convex Mirror