Compare and contrast refraction and diffraction

Refraction is when waves, whether physical or electromagnetic, are deflected when the waves go through a substance. The wave generally changes the angle of its general direction ... Diffraction is when a wave goes through a small hole and has a flared out geometric shadow of the slit. Diffraction is a characteristic of waves of all types. We can hear around a corner because of the diffraction of sound waves. For instance, if a wall is next to you when you yell, the sound will parallel the wall. The wall may stop, but the voice doesn't; sound will almost turn the corner of the wall.

They both can happen to light waves refraction is bending going from one medium to another diffraction is where waves spread out through a hole or interfere through slits