Ātman:- the innermost Self
We as individuals are also a part of this changing universe. Our bodies are constantly undergoing change, while our minds, formed of thoughts and feelings, are also in a state of flux. According to Vedānta, however, our self consists of more than mind and body. At its core lies the unchanging ātman, our innermost, transcendental Self, as opposed to the material self (our body, thoughts, and feelings) that is part of the universe. The ātman is our True Self. But we lose sight of it because of our passionate involvement with our material self and its search for happiness in this universe. The universe can never provide perfect and permanent happiness, however, because it, like our material self, is in a state of constant flux. We attain true happiness only through an awareness of our ātman and the discovery of its true relationship with Brahman.
By achieving awareness of ātman and its unity with Brahman, we attain not only happiness, but also moksha, or liberation. But liberation from what? At one level, the liberation is from unhappiness, but the answer provided by Vedānta Hinduism goes deeper: Moksha is liberation from a chain of lives called samsāra.