Tensor Product Surfaces:

The tensor product method constructs surfaces by "multiplying" two curves. Specified two Bézier, B-spline or NURBS curves, the tensor product method built up a surface by multiplying the basis function of the first curve along with the basis function of the second and utilizes the results as the basis function for a set of two-dimensional control points. Surfaces produced this way are called as  tensor product surfaces. Thus, Bézier surfaces, B-spline surfaces and NURBS surfaces are all of tensor product surfaces.