"This study will related various stories and episodes of the Buddha's many incarnations, including his final one, as they appear in the literature and art of Asia. On the one hand, they represent a vital interest in the Buddha as a teacher and example of righteous behavior, which is central to Hinayana, or Theravada [Doctrine of the elders], Buddhism. On the other hand, the miraculous content of so many of these stories reveals an aspect of the other main branch of Buddhism, Mahayana [The great vehicle] Buddhism. The stories about the past lives of the Buddha are called Jatakas or Birth Stories."
-- from Introduction (p. 2)