Not sure if “contouring” is the right term but maybe I can describe the scenario a bit better.
for the easiest example of this I can think of would be this.
you have a human head model, you have an extruded plane, you want to have the plane contour to the shape of the head (think putting a towel on your head).
another example:
you have a sphere, and a cube, you want the face of the cube to mate up to he curve of the face of the cube
I hope this makes sense.
Sorry if this is not obvious (or is obvious and I have missed it)