Here's a breakdown:

* Refraction occurs when a wave (like light or sound) passes from one medium to another.

* The change in speed of the wave as it enters the new medium causes the wave to bend.

* The angle of bending depends on the difference in speed between the two mediums.

Example: When light travels from air to water, it slows down. This change in speed causes the light to bend, making objects underwater appear in a different position than they actually are.