What is reflection?

When a ray of light falls on a smooth and shiny surface, the whole of light is sent back in the same direction. It is called reflection. Mirrors do not allow even a small amount of light to pass through them. Mirrors show regular and complete reflection.When all the parallel rays reflected from a plane are not parallel, the reflection is diffused or irregular. This is not violation of law of reflection, the reason for diffused reflection is due to irregularities in the reflecting surface.