[Nils]

They are the same race. The Eldar and Avari could and did live together and most probably intermarried. Not all who went on the Great Journey made it to the Blessed Land and some that did came back. After the destruction of Beleriand, the Eldar who remained in Middle-earth were forced to migrate East into the land of the Avari. The Eldar were fewer in number, but much more advanced, especially when it came to fighting wars.