In the Dzogchen tradition in Tibetan Buddhism ground is the primordial state. It is an essential component of the Dzogchen tradition for both the Bonpo and the Nyingmapa. Knowledge of this Ground is called rigpa.
Dzogchen or "Great Perfection", Sanskrit: अतियोग, is a tradition of teachings in Tibetan Buddhism aimed at discovering and continuing in the natural primordial state of being.
Dzogchen developed in the Tibetan Empire period and the Era of Fragmentation (9th-11th centuries) and continues to be practiced today both in Tibet and around the world.
It is a central teaching of the Nyingma school of Tibetan Buddhism and of Bon. In these traditions, Dzogchen is the highest .
In Tibetan Buddhist scholasticism, Buddhist philosophy is traditionally propounded according to a hierarchical classification of four classical Indian philosophical schools, known as the "four tenets" (drubta shyi).
While the classical tenets-system is limited to four tenets (Vaibhāṣika, Sautrāntika, Yogācāra, and Madhyamaka), there are further sub-classifications within these different tenets.
This classification does not include Theravada, the only surviving of the 18 classical schools of Buddhism.
It also does not include other Indian Buddhist schools, such as .