Alfheim is one of the Nine Worlds of Norse cosmology, the luminous realm of the ljosalfar, the "light-elves," radiant beings associated with beauty and benevolence. The chief source, Snorri Sturluson's Prose Edda, records that Alfheim was given to the god Freyr as a "tooth-gift" in his infancy, linking the realm of light and the elves to Freyr's domain of fertility, sunshine, and prosperity.
The Eddic sources say little more, and the elves of Norse belief are genuinely obscure: the light-elves of Alfheim are set against the dark-elves (dokkalfar) or black-elves who dwell underground, and scholars debate how far this neat division reflects genuine pre-Christian belief and how far it is Snorri's own systematizing. What is clear is that the elves were objects of real cult, the sources mention sacrifices to them, the alfablot, and occupied a place, alongside gods and ancestors, in the everyday religion of the Norse. Alfheim stands in the cosmology as one of the fairer and higher of the Nine Worlds, the bright counterpart to the shadowed realms below.