orcs/goblins

[Lord Syslox of Emyn Beverli]

If you closly (and i mean CLOSELY) read The Two Towers, especially the parts concerning Merry & Pippen's being dragged across Rohan and Aragorn following the trail, you will discover that there are a number of different types of orcs.

I agree that goblin is a word that Tolkien used in the Hobbit for orcs (if you read the preface of the hobbit it says something about this i believe), but as the appendices of LotR states, Uruk and Uruk-hai are the big half orcs half men that could go in the sun.

During M & P captivity, there are other orcs present, the orcs or Mordor (eg Grishnahk) appear to be slightly shorter than the Isengarders with bow legs and long arms. Whether these are the Uruks of Mordor or the normal type of Mordor, i dont know. They seem to stand the sun like the Isengarders, but they dont seem as strong as the Isengarders.

The orcs of the Misty Mountains, are shorter again, and cant stand the sun at all. Ugluk says somewhere that the only thing they're good at is seeing in the dark.

In the Two Towers and Return of the King
in Mordor, the "army" orcs call themselves Uruks and the smaller ones snaga (slave). The smaller types must be similar to the Misty Mts type.

Anyway, thats my reading of it, you can make up your own minds.