In Vajrayana Buddhism, the Womb Realm is the metaphysical space inhabited by the Five Compassion Buddhas. The Womb Realm is based on the Mahavairocana Tantra. The name of the mandala derives from chapter 2 of the sutra, where it is said that the buddha Mahāvairocana revealed the mandala's secret teachings to his disciple Vajrasattva from his "womb of compassion". In other translations, the term Matrix Realm or Matrix Mandala is used.

Amitābha is the principal Buddha of Pure Land Buddhism. He is also known as Amitāyus, which is understood to be his enjoyment body (Saṃbhogakāya). In Vajrayana Buddhism, Amitābha is known for his longevity, discernment, pure perception, and the purification of aggregates with deep awareness of the emptiness of all phenomena. The name Amitābha means "Infinite Light", and the name Amitāyus means "Infinite Life".