The Istari, or Wizards, are a group of five Maiar (angelic beings) sent by the Valar (gods) to Middle-earth to oppose Sauron and aid the Free Peoples. The five wizards are:
* Gandalf the Grey (later Gandalf the White): The most well-known wizard, wise and powerful, instrumental in the defeat of Sauron.
* Saruman the White (later Saruman of Many Colours): Initially a powerful ally, Saruman fell to the allure of power and became Sauron's servant.
* Radagast the Brown: A nature-lover, often seen tending to animals and plants. He was a vital, if sometimes eccentric, ally to the Free Peoples.
* Alatar and Pallando (The Blue Wizards): These two wizards are mentioned briefly, but much about them is shrouded in mystery. They went east and their actions are not explicitly described.
So, while we don't see much of Alatar and Pallando in the books, they are still considered Istari and therefore wizards. This means there are actually five wizards in Tolkien's legendarium.