Prism

A prism is a polyhedron with two congruent and parallel faces (called the bases) whose remaining faces (called the lateral faces) are parallelograms. So a prism is a portion of space enclosed by polygons, with specific properties. Prisms are named after the shape of their base faces. For example, if the bases are pentagons then the prism is a pentagonal prism.

If the lateral faces are all perpendicular to the base then the prism is called a right prism. Hence a cuboid is a right rectangular prism, since the base faces are both rectangular. The volume of a prism is the product of the area of a base polygon and the altitude (or vertical height) of the prism.