Elves in D&D are not Tolkien Elves. They are a slight mix of Tolkien, but also ideas from other books and mythology. Tolkien’s elves were tall, usually taller than men. They were powerful. They are likened to angels. An elf lord in Tolkien’s world was someone you did not want to meet in battle.

In D&D, they are short with pointy ears. They have a long life-span, but can’t gain the power as counted in levels of experience, while humans have no limit. This is in AD&D 1st edition. I believe that 2nd edition removed that limit. Some explain this that elves are on the decline and humans are rising. This is a concept from Tolkien. I don’t like the limit. An elf may have a millennium plus lifespan, but it gets more difficult to advance in levels the higher you go. Adventuring is dangerous. After a while elves would retire from adventuring and spend their time building their territory, or studying magic and making items. Without elves of sufficient level to make items, where do all the magical elvish items come from?