Tolkein originally had the "tall, beautiful, elder people" race to be fairies in his earlier stories. The elves in The Hobbit were very different from what they ended up being in Lord of the Rings. They were more mischievous and Santa Claus elf-like. It looks like he combined the two ideas for his later books.
He called them fairies in the beginning (in what is now the Silmarillion), but they were always taller and more beautiful than humans, always immortal in some way, and always arrived before humans.
He simply changed his names for them, as he also did with the 3 main race names.
