Ātman is a Sanskrit word for the true or eternal Self or the self-existent essence or impersonal witness-consciousness within each individual. Atman is conceptually different from Jīvātman, which persists across multiple bodies and lifetimes. Some schools of Indian philosophy regard the Ātman as distinct from the material or mortal ego (Ahamkara), the emotional aspect of the mind (Citta), and existence in an embodied form (Prakṛti). The term is often translated as soul, but is better translated as "Self", as it solely refers to pure consciousness or witness-consciousness, beyond identification with phenomena. In order to attain moksha (liberation), a human being must acquire self-knowledge.

Reincarnation, also known as rebirth or transmigration, is the philosophical or religious concept that the non-physical essence of a living being begins a new life in a different physical form or body after biological death. In most beliefs involving reincarnation, the soul of a human being is immortal and does not disperse after the physical body has perished. Upon death, the soul merely becomes transmigrated into a newborn baby or an animal to continue its immortality. The term transmigration means the passing of a soul from one body to another after death.