Does Curve Fitting Tool 'cubicinterp' method use bicubic interpolation?

The Curve Fitting Tool has an Interpolant Fitting Method of 'cubicinterp' which, it says here, uses cubic spline interpolation, a method that "fits a different cubic polynomial between each pair of data points for curves, or between sets of three points for surfaces." This is NOT the same as bicubic interpolation, right? My understanding is that bicubic interpolation does cubic interpolation between pairs of points first in one dimension, then in the other, which is not the same as fitting a cubic polynomial between 3 points. But I would like to get confirmation from an expert.

Thanks,

Neil