Yes, the pump operating point is defined by the intersection of the system curve with the pump performance curve. You have some influence over the location of the intersection, e.g. moving the pump curve toward the origin by driving the pump at a lower rpm, or by adjusting the system resistance to scale that curve up or down.
The pump manufacturer provides a set of performance curves for a range of drive speeds and sometimes a range of impeller diameters. Superimposed on that you should find roughly elliptical curves representing the loci of constant efficiency operating points. It's customary, absent other constraints, to target your system's operaing point(s) somewhere within the highest efficiency region.
Mike Halloran
Pembroke Pines, FL, USA