Who is Elves from The Silmarillion and what is their importance?

The Elves are the Firstborn or the First Children of Iluvatar. Once they awake, Melkor bombards them with darkness, causing them to be afraid of the Valar. Once Orome discovers and befriends some of them, the Elves are separated into two groups: the Avari and the Eldar. The Avari are the Unwilling or the Refusers, who refuse to march west from Cuivienen. They are also referred to as Moriquendi or Dark Elves and includes any Elf who did not cross the Great Sea to Valinor. During the Noldor's exile, Avari is often used to describe any of the Elves of Middle-earth that are not Noldor or Sindar. Eldar, or Eldalie, means People of the Stars, while Calaquendi means Elves of the Light, but both refer to the Elves who live or had lived in Aman. They are also known as High Elves or Tareldar. The Eldar refer to the Noldor, Teleri and Vanyar who marched westward to Valinor from Cuivienen.