Well it's bit more complicated then that. I've put some effort into studying the mythology of my (possible) ancestors, and frankly the Norse made a real mess of things. I guess that's what you get when every darn tribe has it's own oral tradition. Basically you got Alfar who are sort of like humans, only better in almost every possible way. Fair skinned, blond and all other ways "supernorse". Possibly they are the remnant of a bronze age pantheon later replaced by the Aesir of viking fame. From what I know they sort the "deux ex machina" in norse stories. "An elf did it!"
A svartalf, or dökkalf, is a dwarf. Also a troll. And an elf.
They are either very ugly or very beatiful. They live beneath the ground, having been born from the maggots that fed on the corpse of the world giant Ymir. Adept smiths and powerful magic users. Got dark skin and black hair (black as pitch). Very nature associated, in that when bad things happen in the wilds a dark elf is involved somehow. The early bogeymen of the norse. They later "evolved" into all kinds of weird things and then got a general label as "devils" when christianity became the trend.
