Within the Puranic tradition, there is a long-standing understanding that these sacred narratives are organized into two great sets: eighteen Mahāpurāṇas, or major Puranas, and eighteen Upapurāṇas, or minor Puranas. The Mahāpurāṇas are regarded as the primary, foundational corpus, and they are often described as encompassing the five classic topics known as pañca–lakṣaṇa: creation, dissolution and re-creation, genealogies of gods and sages, cycles of Manus, and the histories of royal lineages. Alongside them, the Upapurāṇas are acknowledged as a parallel group of eighteen texts that complement and extend the themes of the major works, though their lists and attributions are less uniform across traditions. Together, these thirty-six texts form a kind of mythic map of the cosmos, the gods, and the moral order, shaping how many practitioners understand both the visible and invisible dimensions of existence.

The Mahāpurāṇas are further arranged into three groups of six, each associated with a predominant deity and a corresponding quality or orientation. One group is devoted primarily to Viṣṇu and is linked with the quality of sattva, or purity and clarity; this set includes the Viṣṇu Purāṇa, Bhāgavata Purāṇa, Nārada Purāṇa, Garuḍa Purāṇa, Padma Purāṇa, and Varāha Purāṇa. A second group centers on Brahmā and is associated with rajas, the quality of activity and projection; here belong the Brahma Purāṇa, Brahmāṇḍa Purāṇa, Brahmavaivarta Purāṇa, Mārkaṇḍeya Purāṇa, Bhaviṣya Purāṇa, and Vāmana Purāṇa. The third group is oriented toward Śiva and is linked with tamas, the quality of inertia and obscuration; this includes the Matsya Purāṇa, Kūrma Purāṇa, Liṅga Purāṇa, Śiva Purāṇa, Skanda Purāṇa, and Agni Purāṇa. Although each text may honor many deities, this tripartite classification highlights the dominant theological and spiritual emphasis of each group.

The Upapurāṇas, while also traditionally counted as eighteen, are described in more fluid terms, and different lineages preserve somewhat different enumerations and emphases. They are generally portrayed as supplementary to the Mahāpurāṇas, often elaborating specific deities, particular sacred regions, or more specialized strands of doctrine and practice. This very variability can be seen as part of their spiritual function: they allow the Puranic vision to adapt to diverse communities and devotional currents while still echoing the larger cosmological and ethical framework of the major texts. In this way, the distinction between “major” and “minor” does not merely indicate rank, but also suggests a dynamic interplay between a stable canonical core and a more flexible, responsive outer ring of sacred storytelling.