The classification of all aspects of Buddha’s teachings into twelve types: sūtra, geya, vyākaraṇa, gāthā, udāna, nidāna, avadāna, itivṛttaka, jātaka, vaipulya, adbhutadharma, and upadeśa (see individual terms).

Respectively, the sūtras, literally “threads,” does not mean entire texts as in the general meaning of sūtra but the prose passages within texts; the geyas are the verse versions of preceding prose passages; the vyākaraṇas are prophecies; the gāthās are stand-alone verses; the udānas are teachings not given in response to a request; the nidānas are the introductory sections; the avadānas are accounts of the previous lives of individuals who were alive at the time of the Buddha; the itivṛttakas are biographies of buddhas and bodhisattvas in the past; the jātakas are the Buddha’s accounts of his own previous lifetimes; the vaipulyas are teachings that expand upon a certain subject; the adbhutadharmas are descriptions of miracles; and the upadeśas are explanations of terms and categories.