They aren't, really. There's not much to eat except lichens, waters, and other cave-dwelling creatures. Its a very hard environment and not all drow are the friendliest of people.

[Though she is careful not to paint too broad of an allusion.]

Elves are... the people of the wood, originally. They sprung out from the blood of their creator, Corelion, I think? It is said that long ago, the elves were the first people of the land... Ahbehr-Tayril, if I am remembering right. But, anyways, they are a long-lived people and guardians of their ancient areas. Eventually they made their own groups, some going underground, some going to the stars, some returning to the faewyld, some going to the sea, and some traveling the lands.

They are a long lived people, and slow to trust. I have met a few of them in my travels, and they are a good people, if a bit... proud.