Are orcs and goblins really the same in The Hobbit and LotR, and where does it say that? Are they variant sub-races or something, explaining the different physical attributes? Or is my assumption they were different from the different terminology in the Hobbit and LotR novels, and then reinforced by a non-canon interpretation by Jackson in his films?
I recently re-read and then watched the movie of The Hobbit. It made me do some research on Azog the Defiler, as he was in the movie but wasn't in the book itself but in various other Tolkien-bits. I saw that his son Bolg then led the goblins of Moria, which seemed odd, and then I stumbled across something that really confused me, which is the much-wiki'ed claim that orcs and goblins are the same thing.
I had never heard that before, and I read The Hobbit originally some 30 years ago and then again a couple times over the years, and Lord of the Rings at least twice since. It never really crossed my mind that they weren't separate kinds of humanoids (and in fact I was a little griped at them inserting orcs rather than goblins as the foes in the Hobbit movie). It seems odd, especially since there's the whole 'the goblins won't go out during the day' thing, but in both LotR and at least the film Hobbit, the orcs seem all large and in charge during the day and certainly seem physically different from goblins in all the representations I've seen.
I know there are the Uruk-hai which are even more buff and light-tolerant orcs, but the goblins, both in my book recollections and in their depictions in the movies, seem different even from rank and file orcs. In the films they spider climb all over the walls and ceilings (both in Moria and in the Great Goblin's place - if orcs could do that the siege of Helm's Deep would have been over in ~30 seconds) and unwillingness to, even enraged, go out during the day when even the non-Uruk orcs in the Hobbit film are tooling around on wolfback at noontime. I know hobbits are referred to both as "hobbits" and "halflings" by different races, but the references to orcs and goblins don't seem to be split in a logical way where one could claim they're just different words for the same thing...