RAF = Recruit a Friend (<-- this link takes you to google search page, first result is blizz's FAQ about RAF)
RAF Botting is that U team up in a group with your other toons (and have them all controlled by bots), and you can play one toon which the rest will follow etc. Like multiboxing, but then multibotting
If the leaders mounts up, the rest mounts up too. If the leader shares quests, the rest accepts it too. Turn in of quests works as well as far as I'm aware.
If the leader attacks, the rest assists in DPS, Healing or even tanking. So frankly U can run your own dungeon group with RAF if you have 5 accounts and 5 toons of which 1 is tank, 3 DPS and 1 healer. Use the appropriate CC's and off you go with your own team.