A vision quest is believed by the Native Americans to be a way to find answers. It is the same for the Charmed Ones.
It's
believed as a rite of passage. Its the turning point in life taken
before puberty to help them choose the right path for their lives. In
the vision you will be given an animal as a guide and your path becomes
revealed when you are most worthy for it. Once returned they shall take
the proper steps to follow their shown path.
Phoebe took a vision
quest and she met her guide [a wolf] and it took her to a person who
asked if she is ready. Your quest puts you through challenges to see if
you are worthy.