Gandalf the Grey (also known as Gandalf Greyhame by the people of Rohan) is a Wizard who is well known in Middle-Earth. He has best fireworks as Sam said, he uses his Staff and the elvensword Glamdring which he found in a troll cave. All the hobbits in Hobbiton (Hobbiton is a little part of the Shire) think that he is just all fun and games, but they don't know his real reason for coming to the Shire.One more thing to tell you before I leave this part is that Gandalf is a servant of the Secret Fire, a wielder of the flame of Anor which is a elvish ring, as he says when he is fighting the Balrog
The first time we meet this wizard is in The Hobbit where he is trying to find a brave person to go with thirteen dwarves to get back their treasure from a Dragon named Smaug. His next appearance is in The Lord of the Rings books, where he and a Fellowship of Men, Elves, Dwarves, and Hobbits are trying to destroy the One Ring that belonged to the dark lord Sauron.
If you haven't read the book, I'll give you a brief story of The Lord of the Rings that has to do with Gandalf.
Gandalf is on his way to Hobbiton for Bilbo Baggins and Frodo Baggins birthday that night Bilbo mysteriously vanishes. Gandalf finds Bilbo back at his Hobbit Hole about to leave the Shire forever. Bilbo is going to leave everything to his nephew Frodo, except for his magical ring, (he uses this ring to vanish because if you put the ring on it makes you go invisable.)so Gandalf helps him to let the ring go. Gandalf then gives the ring to Frodo and leaves for Gondor to get some questions answered.
Gandalf then returns to the Shire to give Frodo some news about the ring. He tells him that the ring actually belonged to the dark lord Sauron who used the ring to enslave all of Middle-Earth. He also tells Frodo that they need to take the ring to the one place it can be destroyed, the very place that it was made Mount Doom (The ring could also be destroyed by the fire of a Dragon, but since there is no dragons that are known to them excect for Smaug who was killed).
Gandalf tells that he would meet the hobbits at The Prancing Pony in Bree then go with them to Rivendale; because he needed to go to Isengard to see the head of his council Sarumon. Frodo gets some friends to help him there's Samwise Gamgee, Mariadoc Brandybuck, and Peregrin Took. So the hobbits go to Bree and Gandalf goes to Isengard. When Gandalf gets there he learns that Saruman is evil. Saruman imprisons Gandalf but Gandalf escapes. He meets back with the Hobbits in Rivendale.
The little company picked up some more people to help them on their quest, there was Aragorn son of Arathorn the king of Gondor (The Hobbits actually met up with Aragorn in Bree.), Boromir of Gondor, Legolas of the Elves of Mirkwood, and Gimli son of Gloin of the Dwarves from Erebor. The new Fellowship went south alond the Misty Mountains into the Mines of Moria where they were attacked by orcs. They fled to the bridge of Khazad-dum where they were attacked by a Balrog a fire demon, the fire of Udun. Gandalf destroyed the bridge and the Balrog fell into the abyss dragging Gandalf with it. Gandalf followed his foe to Balins Tower were he defeated the Balrog, But in doing this he also died. Since Gandalf sacrificed himself for his friends the Valar brought him back in White!