The Vishnu Purana (Viṣṇu Purāṇa) is a religious Hindu text and one of the (most important) eighteen Mahapuranas. It is also known as Puranaratna ("gem of Puranas"). Presented as a dialogue between Parashara and his disciple Maitreya, the major topics discussed include creation, stories of battles fought between asuras and devas, the Avat...
Now the Vishnu Purana describes what the Puranas are and how they came to written. It says that the original text Purana Samhita was taught by Vedavyasa to his disciple Romaharshana (also called Lomaharshana). Romaharshana had six disciples, Sumati, Agnivarchah, Mitrayu, Shamshapayana, Akritavrana and Savarni. Each of these disciples composed a Purana on the basis of the Purana Samhita. It was on the basis of these that the Vishnu Purana had written. It was written after the Padma Purana and is devoted to the glory of Lord Vishnu.
There are fourteen types of knowledge (vidya). These are the four Vedas, the six Vedangas, Mimamasa, Nyaya, the Puranas and the Dharmashastras. To this one might add four further forms of knowledge, Ayurveda, Dhanurveda, music and Arthashastra. There are three types of rishis, brahmarshis, devarshis and rajarshis.