The Puranas are a genre of important Hindu religious texts that provide information about ancient Indian history, genealogies of kings, devas, and sages, and various rituals. There are 18 main Puranas that cover topics like cosmology, genealogy, and mythology. The oldest Purana is the Vishnu Purana, which focuses on Vishnu and his avatars. The largest Purana is the Skanda Purana, which influenced Hindu traditions related to the god Skanda. The Puranas have had a major impact on Indian traditions, festivals, rituals, arts, culture, and pilgrimage sites.