Nikāya (निकाय) is a Pāli word meaning "volume". It is often used like the Sanskrit word āgama (आगम) to mean "collection", "assemblage", "class" or "group" in both Pāḷi and Sanskrit. It is most commonly used in reference to the Pali Buddhist texts of the Tripitaka namely those found in the Sutta Piṭaka. It is also used to refer to monastic lineages, where it is sometimes translated as a 'monastic fraternity'.
Theravāda is the most commonly accepted name of Buddhism's oldest existing school.
The school's adherents, termed Theravādins, have preserved their version of Gautama Buddha's teaching or Buddha Dhamma in the Pāli Canon for over a millennium.
The Pāli Canon is the most complete Buddhist canon surviving in a classical Indian language, Pāli, which serves as the school's sacred language and lingua franca.
In contrast to Mahāyāna and Vajrayāna, Theravāda tends to be conservative in matters of .