In the Norse Cosmology there are nine worlds where all of the beings live, they are complex and very important to Asatru.
Norsemen visualized the universe as nine worlds: three sets of three, on three different "levels".
At the top was Ásgarð, the home of the Æsir. Each of the gods and goddesses had their halls here, enclosed by the stone wall built by the giant mason. Also on this level was Vanaheim, home of the Vanir, the deities with whom the Æsir fought the first war, which ended in a draw. Thirdly, Alfheim was located on this level, the home of the light elves. None of the surviving literature describes the relationship between the light elves and the Æsir, except to note that they were regularly in one another's company.
The middle level contained Miðgarð, the middle world inhabited by men. It was surrounded by an ocean so vast that "to cross it would strike most men as impossible". Jörmangandr, the terrifying world serpent, lay on the floor of the ocean. Jötenheim, the land of the giants, lay outside Miðgarð to the east, in Útgarð, the outer world. To the north lived the dwarves in Nidavellir and the dark elves in Svartalfheim. Connecting Miðgarð to Ásgarð was Bifröst, the rainbow bridge guarded by Heimdall.
The lower level contained Niflheim, the world of the dead. Hel ruled here. The ninth world was Muspellheim, land of the fire giants, which can't be located precisely, except to say that it was to the south." (1)