Why embarrassed? If you got the term wrong the worst that's going to happen is that you're going to momentarily confuse whoever it is you're talking to if they happen to be more familiar with it than you are. The biggest problem I have with not knowing terms is having trouble searching if I need help with something XD
On this particular example my understanding is that normal maps just make low poly look like higher poly without adding geometry, but displacement was better if you wanted better shadows and to actually see bumps close up (because normal maps apparently didn't do shadows well or at all and if you zoom in enough you can see that the bumps are a lie XD). I don't know if there are different ways to use them, think just the painting is slightly different? I've just been plugging a map into the "displacement" connector on the output node and that seems to do the job :S
My youngest son loves Bioshock :) I haven't had time to game for a while x_x