Question

whats the difference between cuboid and rectangular prism?

Answer 1

Cuboid has a square cross sectional area and a length perhaps different from the side of the cross section.  It has 8 vertices, 12 sides, 6 faces.

It is like a cube, but one dimension is different from the other two.  All the angles are 90 degrees at the vertices or edges.  Cuboid stands vertically if you make it stand on the cross section.

Rectangular prism has a rectangular cross section.  If you make it stand on the cross sectional base,  it may not stand vertical.   It can be oblique or oblong. That is it may tilt to one side.  So all the vertical faces remain parallel and tilt in one direction at an angle.

A Right rectangular prism is same as a cuboid.  It has 8 vertices, 12 sides, 6 faces.