A transparent object with smooth and polished surfaces which refract the light is known as prism.
There are several types of prism but the traditional one is triangular prism.
The cross-section of the prism will be polygon. (Edges are straight).
Prism will not have curved surfaces.
A prism can be enclosed by any number of surfaces.
The sides of the prism are not parallel.
The shape of the base (or cross section) gives the name of the prism.
Example: Triangular prism:
A. Triangular prism is constructed with two triangular bases and three rectangular sides.
B. The two place surfaces meet along an edge at a certain angle as shown in figure.
C. The plane surfaces are called refracting surfaces.
If a narrow beam of white light is passed through a prism, it splits into seven colours known as spectrum.
Red light is bent least by the prism. Violet light is deviated most by the same prism.