It is almost unknown outside of Tolkien and Tolkien derivatives to make any distinction between a elf and a dwarf, an orc and a goblin.
In fact elves, fairies, sprites, pixies, leprechauns, dwarves, goblins, gnomes, dryads are all usually classified as fey in mythical material.
Not sure about orcs, never saw the word until I read Tolkien. Maybe I can find it in the OED? Dictionary.com refers to grampus from Milton, grampus is apparently a Killer Whale or something of the kind.
Sometimes people make distinctions such as fairies and goblins, fairies being nicer than the ugly goblins, but that is inconsistent. You usually find that when someone is imposing a Christian derived moral dualism on fairy.