Bicubic Patches
By taking a set of four cubic curves with parameter \(s\) and using these four curves to generate a set of four control points for any given value of \(s\), and then using these control points to define a parametric curve with parameter \(t\) we can generate a surface called a bicubic patch.
https://www.inf.ed.ac.uk/teaching/courses/cg/d3/bezierPatch.html