Trikaya — The Three Bodies of the Absolute
The Trikaya (three bodies) doctrine of Vajrayana Buddhism describes the three dimensions of enlightened existence: Dharmakaya (truth body), Sambhogakaya (enjoyment body), and Nirmanakaya (emanation body).
The Trikaya (three bodies) doctrine is the Vajrayana Buddhist analysis of the dimensions of enlightened being — not three separate bodies but three aspects of the one enlightened reality. Dharmakaya (truth body) is the absolute, formless, empty dimension of Buddhahood — pure awareness without any object, the equivalent of Kashmir Shaivism's Paramashiva. Sambhogakaya (enjoyment/bliss body) is the subtlest form dimension — the luminous, blissful subtle body of the Buddha visible only to advanced practitioners, corresponding to the five Buddha families and their mandalas. Nirmanakaya (emanation/manifestation body) is the grossest form dimension — the physical manifestation of enlightenment visible to all beings, including the historical Shakyamuni Buddha. For the practitioner, these three correspond to the three experiences of death (Dharmakaya), bardo (Sambhogakaya), and rebirth (Nirmanakaya) — and Vajrayana practice trains the practitioner to recognize and utilize all three.
The three bodies of the Buddha are not three but one — the one reality appearing as formlessness, subtle form, and gross form simultaneously.
Philosopher Ken Wilber's 'three faces of Spirit' (first-person, second-person, and third-person dimensions of the divine) maps onto the Trikaya in an interesting way: Dharmakaya as the first-person 'I am' awareness, Sambhogakaya as the second-person 'Thou' of devotional encounter, Nirmanakaya as the third-person 'It' of the manifest world.
Dharmadhatu Stava