The five periods are therefore an example of skillful means, in which the Buddha adapted his basic teachings to match the differing capacities of his changing public clientele.
According to Zhiyi, the five periods of the Buddha’s teaching were:
(1) The Flower Garland (Avatamsaka Sutra) Period, for three weeks after the Buddha attained enlightenment. In this period, the Buddha supposedly taught that there were countless Buddhist universes.
This teaching described the bodhisattva’s path through ten stages. It also discusses the development of bodhicitta (the seed of enlightenment, to be developed in the bodhisattva’s practice).