orcs and goblins- what's the difference???

[Firefoot]

yes well although obviously they originated the same way goblins and orcs are now two unique groups that can be set apart easily goblins are smaller not because they're wimpy but rather so they need less food which is scarce in the mountains while it was said earlier orcs are bigger because sauron was pumping them up.

Sorry, Morsul, but you're not convincing me. Do you have any textual proof to back this up? Everything I have seen definitely points to the two being the same.