Second, the Tripitaka is a series of Buddhist classics. Also known as Zhu Jing, Qi Jing, Tibetan Jing or Sanzang. The content includes classics (including the preaching of Sakyamuni when he was alive, and the preaching of a few Buddhists-Arhat or Bodhisattva), laws (etiquette rules formulated by Sakyamuni for believers) and theories (explanations or explanations of Buddhist teachings). The compilation of the Tripitaka began shortly after Sakyamuni's nirvana. In order to preserve his sermon and unify the views and understanding of believers, the disciples formed unanimously recognized contents of classics, law and theory through meetings. Later, it added "Tibetan classics" such as classics, jurisprudence and theory, which became four categories. After the split of primitive Buddhism, most of the major factions compiled their own Tibetan scriptures according to their own views, and only Sanzang, the seated monk, kept it relatively intact.