Answer
Circular paraboloid, opening upward (along z) with vertex at (0,0,1).
Work Step by Step
Trace in x=0: parabola, vertex at (0,0,1), opens up.
Trace in y=0: parabola, vertex at (0,0,1), opens up.
Traces when z is below 1: none.
Traces for z above 1: circles, $x^{2}+y^{2}=k^{2}.$
Graph: circular paraboloid, opening upward (along z) with vertex at (0,0,1).