There are lots of graphics objects, each with handles. Why not read the documentation, which explains exactly how they are arranged:
Note that keeping and using the actual handle is always going to be faster an more robust. This is much better:
h = surf(...)
than anything involving gcf, gca, or findobj. You should think of these as conveniences for you while playing around in the command window, but never use them for serious code. They are far too unpredictable!
