Question

What is reflection and refraction of light ?

Answer 1

Whenever light travelling in a straight line hits any surface, it is is either absorbed or reflected. Bouncing back of light rays after hitting any surface is called reflection of light. 

The densities of all media are different, hence the speed of light varies as it passes from one medium to the other. Bending of light rays as they pass from one medium to the other is called refraction of light.