In Buddhism, Maitreya Buddha is the future Buddha.
Maitreya is a bodhisattva who Buddhists believe will eventually appear on earth, achieve complete enlightenment, and teach the pure dharma. Maitreya is comparable to second coming prophecies in other religions, such as the coming of Kalki, the final avatar of Vishnu, in Hinduism, the return of Jesus in Christianity, or of Saoshyant in Zoroastrianism.
Maitreya is typically depicted sitting on an altar with both feet on the ground, indicating that he has not yet completed ascending his throne.
