They were more beautiful than anyone else. Tolkien was based on this word to create the Eldamar word in the language of the Elves. On the other hand, in other accounts it gives to understand that Elves live in forests, caves or sources, vision that matches much with the idea that we currently have of the Elves. Relationship with the gods in Norse mythology the Elves are closely related to the Norse gods, which are divided in the asir and Vanir. The asir or ACEs, are the main gods of Norse mythology, and are considered gods of war. Although they are the main, they are not the first; they appear in Norse religion after the Indo-European invasions and they were incorporated into a pantheon of ancient gods, (Vanir) rather than supplant them.
They are related to Odin, and live in Asgard. Some of the asir most famous are the own Odin, Thor, Loki and Tyr. Crashing thinking that Odin, Thor, and the elves have the same source, weird huh? On the other hand are the Vanir gods of fertility, prosperity and the sea. They were rich and givers of wealth, patterns of fertility, pleasure and peace. They had a deep knowledge of the magical arts, so were able to predict the future.
It was said that it was Freyja (main Vanir goddess) who taught magic to the asir. As mentioned before the Elves relates them with both the Aeesir and the Vanir, but the predominant idea is that they were more related to the latter. In fact, in some texts Vanir and the alfar (Elves) term used interchangeably. Both the Vanir and the alfar had powers over the fertility and healing, so it can be assumed that there was a difference of hierarchy between the elves, who were minor fertility deities, and the Vanir who were the main gods. In fact, some poem mentions to Freyr (God of rain, the rising sun and fertility and one of the major Vanir gods) as the ruler of the elves in the Alfheim.