Besides cosmogony, they deal with mythical descriptions of the earth, the doctrine of the cosmic ages, the exploits of ancient gods, saints, and heroes, accounts of the Avatārs of Vishṇu, the genealogies of the Solar and Lunar race of kings, and enumerations of the thousand names of Vishṇu or of Çiva. They also contain rules about the worship of the gods by means of prayers, fastings, votive offerings, festivals, and pilgrimages.
The Garuḍa, as well as the late and unimportant Agni Purāṇa, practically constitute abstracts of the Mahābhārata and the Harivaṃça.
The Vāyu, which appears to be one of the oldest, coincides in part of its matter with the Mahābhārata, but is more closely connected with the Harivaṃça, the passage which deals with the creation of the world often agreeing verbatim with the corresponding part of the latter poem.
The relationship of the Matsya Purāṇa to the great epic and its supplementary book as sources is similarly intimate. It is introduced with the story of Manu and the Fish (Matsya). The Kūrma, besides giving an account of the various Avatārs of Vishṇu (of which the tortoise or kūrma is one), of the genealogies of gods and kings, as well as other matters, contains an extensive account of the world in accordance with the accepted cosmological notions of the Mahābhārata and of the Purāṇas in general. The world is here represented as consisting of seven concentric islands separated by different oceans. The central island, with Mount Meru in the middle, is Jambu-dvīpa, of which Bhārata-varsha, the “kingdom of the Bharatas,” or India, is the main division.
The Mārkaṇḍeya, which expressly recognises the priority of the Mahābhārata, is so called because it is related by the sage Mārkaṇḍeya to explain difficulties suggested by the epic, such as, How could Kṛishṇa become a man? Its leading feature is narrative and it is the least sectarian of the Purāṇas.
The extensive Padma Purāṇa, which contains a great many stones agreeing with those of the Mahābhārata, is, on the other hand, strongly Vishnuite in tone. Yet this, as well as the Mārkaṇḍeya, expressly states the doctrine of the Tri-mūrti or Trinity, that Brahmā, Vishṇu, and Çiva are only one being. This doctrine, already to be found in the Harivaṃça, is not so prominent in post-Vedic literature as is commonly supposed. It is interesting to note that the story of Rāma, as told in the Padma Purāṇa, follows not only the Rāmāyaṇa but also Kālidāsa’s account in the Raghuvaṃça, with which it often agrees literally. Again, the story of Çakuntalā is related, not in accordance with the Mahābhārata, but with Kālidāsa’s drama.
The Brahma-vaivarta Purāṇa is also strongly sectarian in favour of Vishṇu in the form of Kṛishṇa. It is to be noted that both here and in the Padma Purāṇa an important part is played by Kṛishṇa’s mistress Rādhā, who is unknown to the Harivaṃça, the Vishṇu, and even the Bhāgavata Purāṇa.
The Vishṇu Purāṇa, which very often agrees with the Mahābhārata in its subject-matter, corresponds most closely to the Indian definition of a Purāṇa, as treating of the five topics of primary creation, secondary creation, genealogies of gods and patriarchs, reigns of various Manus, and the history of the old dynasties of kings.
The Bhāgavata Purāṇa, which consists of about 18,000 çlokas, derives its name from being dedicated to the glorification of Bhāgavata or Vishṇu. It is later than the Vishṇu, which it presupposes, probably dating from the thirteenth century. It exercises a more powerful influence in India than any other Purāṇa. The most popular part is the tenth book, which narrates in detail the history of Kṛishṇa, and has been translated into perhaps every one of the vernacular languages of India.
Other Vishnuite Purāṇas of a late date are the Brahma, the Nāradīya, the Vāmana, and the Varāha, the latter two called after the Dwarf and the Boar incarnations of Vishṇu.