What is the difference between a rectangular prism and a cuboid
 

For other uses, see Cuboid (disambiguation).

In geometry, a cuboid is a convex polyhedron bounded by six quadrilateral faces, whose polyhedral graph is the same as that of a cube. While mathematical literature refers to any such polyhedron as a cuboid,^[1] other sources use "cuboid" to refer to a shape of this type in which each of the faces is a rectangle (and so each pair of adjacent faces meets in a right angle); this more restrictive type of cuboid is also known as a rectangular cuboid, right cuboid, rectangular box
 

Cuboid shapes are often used for boxes, cupboards, rooms, buildings, etc. Cuboids are among those solids that can tessellate 3-dimensional space. The shape is fairly versatile in being able to contain multiple smaller cuboids, e.g.sugar cubes in a box, boxes in a cupboard, cupboards in a room, and rooms in a building

Cuboids, Rectangular Prisms and Cubes. It has six flat faces and all angles are right angles. It is also a prismbecause it has the same cross-section along a length. In fact it is a rectangular prism.

hope it helps
 

a rectangular prism has 5 faces 

cuboid has 6 faces