The three bodies of a buddha

The "three bodies" (trikāya, from tri, "three," and kāya, "body") is a teaching from the Mahāyāna traditions - the branch of Buddhism centered on compassion for all beings - about what a buddha really is. "Body" here doesn't only mean a physical form; it means something more like a "way of being" or "dimension." The doctrine says a buddha can be understood on three levels at once.

First is the "reality body" or "truth body" (dharmakāya): buddhahood identified with ultimate reality itself - boundless, formless, beyond birth and death. This is what all buddhas share; it is awakening as the very nature of things, not a person at all. Second is the "enjoyment body" (saṃbhogakāya): a radiant, heavenly form in which a buddha appears in exalted realms, teaching advanced practitioners and the great bodhisattvas. The luminous celestial buddhas of devotion, such as Amitābha, are met in this register. Third is the "manifestation body" or "emanation body" (nirmāṇakāya): the ordinary, visible form a buddha takes to appear in the world among people - the historical Buddha who walked, ate, taught, and died is understood this way.

The point of the threefold scheme is to hold two truths together: a buddha is, on one hand, fully identified with timeless reality, and on the other hand, genuinely present and reachable - as a glorious form for the spiritually advanced, and as a flesh-and-blood teacher for the rest of us. It is not three separate beings but three faces of one awakening, systematized by Buddhist thinkers (especially the Yogācāra school) several centuries into the tradition's development.