Question

what is the a refraction??

Answer 1

In optics, refraction is a phenomenon that often occurs when waves travel from a medium with a given refractive index to a medium with another at an oblique angle. At the boundary between the media, the wave's phase velocity is altered, usually causing a change in direction.

Answer 2

refraction means when light goes through one medium to another medium it deflectes in certain angel that calls refraction and the angle is call refraction angle