Gandalf is the wizard who guides Bilbo in J.R.R. Tolkien’s The Hobbit.
Gandalf arranges Bilbo Baggins’s involvement in Thorin Oakenshield’s expedition to the Lonely Mountain. He recognizes that Bilbo’s qualities as a burglar, including discretion and resourcefulness, could be useful to the dwarves’ quest to reclaim their homeland and treasure.
The character is more than a conventional human magician. In Tolkien’s mythology, Gandalf is a Maia, a spiritual being sent to Middle-earth in the form of an old man. His original name in the West is Olórin, and he is known by different names in different languages and places.
In The Lord of the Rings, Gandalf becomes a central opponent of Sauron. His journey from Gandalf the Grey to Gandalf the White is a transformation of authority and purpose, not the introduction of a different character.