Maitreya currently resides in the "" Heaven (Pāli: "Tusita"), said to be reachable through meditation. Gautama Buddha also lived here before he was born into the world as all bodhisattvas live in the Heaven before they descend to the human realm to become Buddhas. Although all bodhisattvas are destined to become Buddhas, the concept of a bodhisattva differs greatly in Theravada and Mahayana Buddhism. In Theravada Buddhism, a bodhisattva is one who is striving for full enlightenment (Arahantship in Pali), whereas in Mahayana Buddhism, a bodhisattva is one who has already reached a very advanced state of grace or enlightenment but holds back from entering nirvana so that he may help others.