Once upon a time, all the Elves were one big happy family. There were no Noldor, Vanyar, or Sindar, Green-elves, Grey Elves or Dark Elves. But after they had all been living for a while in the peace and quiet of Cuivienen, the Elves were discovered by Oromë, and he whisked three of them (Ingwë, Finwë and Elwë) away to the Blessed Realm on the behest of the other Valar – who had decided that they would like the Elves to come and live with them in the light and warmth of Valinor rather than stay in the cold and dark of Middle-earth.
When those three Elves returned, they were full of appreciation for the Blessed Realm and told all those around them of the wonders contained therein. And so when the time came to make a decision, many decided to follow Oromë back to Valinor. These were all of Ingwë’s people, and most of Finwë’s and Elwë’s people. These Elves that decided to leave Cuivienen were then known as the Eldar.
However, many Elves also refused Oromë’s summons, preferring the starlight and wide spaces of Middle-earth. These were known as the Avari.
The Eldar then arranged themselves into three hosts for their journey over to the Blessed Realm:
– Ingwë’s host – the first to set forth and the smallest. His elves were the Vanyar.
– Finwë’s host – the second to set forth and the second smallest. His elves were the Noldor.
– Elwë’s led his host with his brother Olwë because the number of the third host was so large. They were the Teleri.
While the Eldar were travelling across the lands of Middle-earth on their way to the Blessed Realm, some of the Elves turned aside from the journey. The majority of these elves were from the Teleri, who lingered on the road, not sure whether they wanted to leave the twilight of Middle-earth. Some went to live in the forests and mountains of Middle-earth, and others lived by the shores of the Western Sea. And from this winnowing of the Eldar comes a second set of complicated names:
– The elves who went straight on the Great Journey are called Calaquendi – Elves of the Light
– The elves who delayed on the way are called Úmanyar – “those not of Aman”
– The Úmanyar are often grouped with the Avari as both groups never completed the Great Journey. The combined group is known as the Moriquendi (Elves of the Dark).
Or to put it in a picture …

by atalante_star