The term Tripiṭaka means three baskets: (1) basket of sūtras, (2) basket of monastic rules and (3) basket of commentaries. The teachings of the Buddha are thus classified and stored in three categories. The Tripiṭaka is further divided into the Three Learnings: (1) Buddhist precepts (kai), (2) meditation (iō), and (3) wisdom (e). It is sometimes said that there are jō, kai, and e in the order of the Buddha’s preaching; kai, jō, and e in the order of practicing; and e, kai, and jō with regard to the doctrinal teachings. In the precept basket, there are various kinds of precepts such as the Five Precepts, the Eight Precepts, the Ten Good Precepts, the Two Hundred Fifty Precepts, the Five Hundred Precepts and so on. In the meditation basket, there are such meditations as the Ambiguous Meditation, the Pure Meditation, the Meditation without Delusions, and so on. The basket of wisdom refers to the Buddha’s wisdom through which one can understand suffering, voidness, impermanence, egolessness, and so on.

Ichidai Shōgyō Tai-I, Outline of All the Holy Teachings of the Buddha, Writings of Nichiren Shōnin, Doctrine 3, Page 67