The Vayu Purana discusses its theories of cosmology, genealogy of gods and kings of solar and lunar dynasties, mythology, geography, manvantaras, the solar system and the movements of the celestial bodies. In addition to these, the text has chapters which were inserted in the later centuries into the older version of the Vayu Purana, such as chapters 16-17 which discuss duties of the Varna (caste or class) and duties of a person during various Ashrama (stages such as Brahmacharya, Grihastha, Vanaprastha and Sannyasa), chapter 18 which discusses penances for sannyasi (monks, "yati"), chapters 57–59 on dharma, chapters 73 to 83 on sanskaras (rites of passage), and chapter 101 on the theory of hell in after-life.