Final answer:
Refraction is the bending or changing direction of a ray of light when it passes from one medium to another.
Step-by-step explanation:
Refraction is the process of bending or changing the direction of a ray of light when it passes from one medium into another medium.
This phenomenon occurs due to the change in speed of light as it travels from a medium with one optical density to a medium with a different optical density.
For example, when light travels from air to water, it changes direction at the interface between the two media.
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