Question

The three sections, divisions, or periods of Buddha's teaching in his life- time, known as 序分, i.e. the 华严, 阿含, 方等, and 般若stras; 正宗分, i.e. 无量义, 法华, and 普贤观stras; and 流通分, i.e. the 盘经; they are known as introductory, main discourse, and final application. There are other definitions.