Vishnu (; ]; , ) is one of the principal deities of Hinduism. The preserver in the Hindu triad (Trimurti), Vishnu is revered as the supreme being in Vaishnavism as identical to the metaphysical concept of Brahman (Atman, the self, or unchanging ultimate reality), and is notable for adopting various incarnations (such avatars as Rama and Krishna) to preserve and protect dharmic principles whenever the world is threatened with evil, chaos, and destructive forces. In the Smarta Tradition of Hinduism, Vishnu is also one of the five equivalent deities worshipped in Panchayatana puja.