The angle formed between the incident ray and the emergent ray in a prism is known as the angle of deviation.

In a prism, light undergoes bending towards the normal at one surface and away from the normal at the other. In a glass slab, the bending occurs only once, either towards or away from the normal depending on the direction ...

At the second surface AC, the light ray exits from glass to air, bending away from the normal. This is in contrast to the first surface where the bending was towards the normal.

Light is refracted through a transparent prism by passing through its three rectangular lateral surfaces. The triangular glass prism has two triangular bases and three rectangular lateral surfaces that are inclined to each other.

In a glass slab with parallel refracting surfaces, the emergent ray is parallel to the incident ray, but it is slightly displaced laterally.