What is it called when a wave changes direction?

When a wave changes direction, the most accurate term to describe this phenomenon is refraction. Refraction occurs when a wave travels from one medium to another and experiences a change in speed, resulting in a change in direction. This is commonly observed with light waves moving from air into water, which causes the light to bend.

Reflection, on the other hand, describes the process of a wave bouncing back when it hits a barrier, while transmission refers to the process of a wave passing through a medium without being absorbed. The term deviation is less commonly used in the context of wave behavior and may not accurately encapsulate the specific physical processes involved. In the context of waves, refraction is the precise term that highlights the change in direction due to interactions with different media.