A three dimensional projection of a four dimensional figure. Just as a cube is the three dimensional equivalent of a two dimensional cube, a hypercube is the four dimensional equivalent of the cube. Just as we can draw a cube on a page (a two dimensional projection of a three dimensional figure) so we can do the same in three dimensions to project a hypercube.
This was my first simple 3D model just to get the idea of building & how Shapeways works.