Here's why:

* Refraction is the bending of waves as they pass from one medium to another. This happens because the speed of the wave changes as it enters the new medium.

* Examples:

* Light bending as it passes from air to water, causing objects to appear in a different position.

* Sound waves bending as they pass from air to a solid object, allowing you to hear sounds around corners.

Let me know if you'd like more details on refraction!