The bus shuttles Fairies, Fairy Godparents and their Godchildren back and forth from Earth to Fairy World and back. Usually this is used in the case that the fairies do not have access to their magic, otherwise they can just use their wands to teleport themselves to Fairy World. In the episode, Crocker Shocker, both Jorgen von Strangle and Timmy Turner used this bus to get to Earth and Fairy World respectively after all of Fairy World's magic had been drained.