Reflection and refraction of light

Reflection involves a change in the direction of waves when they bounce off a barrier. Reflection can be visualized by a beam of light hitting a mirror.

Refraction of waves involves a change in the direction of waves as they pass from one medium to another. A beam of light traveling from the air through water results in changes in the direction and intensity of light. The path of a light wave bends as it passes across the boundary separating two media. This phenomenon is caused by the change in speed experienced by a wave when it changes medium and the angle of refraction is governed by Snell's Law.