NURBS (Non-Uniform Rational B-Spline) is a mathematical model that is used to create curves and surfaces based on B-spline geometry. These surfaces are defined by a set of 3D vertices of the B-splines that form an M*N array, where M is the count of rows and N is the count of columns.

For more details, see the following topics:

Overview of NURBS Surfaces

Specific Properties of NURBS Surfaces

Working with Control Points of NURBS Surfaces

Computed Properties of NURBS Surfaces

OdDbNurbSurface Class in API Reference

A sample command for working with NURBS surfaces is located in the Drawing\Examples\DevGuideCommands subdirectory of the ODA installation folder.