Curves

Surfaces

Volumes

Curves are made up of a set of points. They can be 2D or 3D. Arcs, rectangles, polylines, and NURBS curves are examples of curves.

Surfaces are made up of facets. They can be can be 2D or 3D. For example, tubes and plane surfaces are surfaces.

Volumes are defined as closed surfaces. For instance, spheres, cubes, and pyramids are volumes.