Fluff text-wise, yes elves trance instead of of sleeping.<br/><br/>Mechanically speaking there is no real difference.  They both have the same limitations and requirements of rest for spellcasters, and awakening from sleep/trance means you're dazed for the round following being woken.<br/><br/>I think it's a silly distinguishment really, but someone somewhere decided they didn't like the idea of elves sleeping.  I'm surprised no one has written in an immunity for elves needing to use the bathroom!  LOL!