The terms Sarga (creation), Pratisarga (secondary creation or dissolution), Vansh (genealogy of gods and sages), and Manvantar (epochs of Manu) collectively define the structure of a Purana. Puranas are ancient Hindu texts that contain narratives of the history of the universe, the genealogies of kings, heroes, and demigods, as well as cosmology and mythology. They are regarded as a vital part of Vedic literature.