Prisms have two congruent -- or identical -- bases, and pyramids only have one base. The shape of the base on pyramids and prisms can vary, depending on the shape of the overall three-dimensional object. For example, the base could have a square, rectangle, triangle, hexagon, pentagon or octagon shape.
Both prisms and pyramids are three-dimensional, which means they have length, width, and height. A prism has two identical bases that are parallel, while a pyramid has one base.
