Question

what is refraction? why does this take place

Answer 1

Refraction is the decease is the speed of light when it passes through a transparent medium

Eg glass water etc.

Answer 2

refraction is when the light travels from certain mediums it bends because of differences in medium and change in its velocities this is called refraction. this takes place because of change in medium and change in velocities
for example, a light entring from rarer to denser will bend toward the normal because of change in medium