NURBS – NURBS (Non Uniform Rational B-Splines) are used to create shapes in 3D space. NURBS curves can have corners similar to a polygon, that is, they can have corner vertices or bezier vertices (square corners or curved corners).
Before Vectorworks offered planar objects, NURBS objects were the only way to create shapes in 3D space. Now that we have planar objects it is not so common to use NURBS for modeling your designs. However, NURBS curves are still extremely useful for some modeling parts of Vectorworks.