Definitions for "Angle of Refraction"
The angle between the ray which is refracted at a surface and the normal to that surface.
(Generally identified as a "numbered" theta, such as 2, but sometimes as .) The angle at which light travels after passing through an interface between two media, measured between the path of the light and the normal to the interface. See this page of this module to learn more about refraction.
The angle formed between the normal and a refracted beam.
is the angle of bending of light when it travels from one medium into another.