There are 18 puranas compiled by the greatest Genius Sage Vyasa as "Puranas".  He used such an brilliant approach of using a real event in history to convey the same message through his historical work, the Mahabharata, the biggest literary work ever composed.   The Puranas narrate the history of the various dynasties and hierarchies that emanated from the supreme Consciousness. As a continuation of the lines of Priyavrata and Uttanapada (vide, the doctrine of creation under the Upanishads, above), the world saw the coming in of many heroes, both spiritual and temporal. These offspring of the ancient ones included both the divine and demoniacal natures, which waged a perpetual war between themselves, and much of the Purana content is devoted to descriptions of these conflicts between the Devas and Asuras.

   Other than these earlier descendants of the progenitors of the race of all beings, particular mention must be made of the lines of the solar and lunar races of kings and sages, whose lives provide a highly interesting biographical reading of both human and superhuman natures. The history of these dynasties is brought down almost to our own times, thus connecting our present-day existence with the diviner sources from which we have come, as, in the words of the Upanishad, children of the Immortal (Amritasya Putra).

   But through these historical events and life of great men, Puranas helps us to understand what is Consciousness, the Mystery of every Human being, whether he or she was in the ancient age or living in this modern age. It is the birth right of every human being to understand the Mystery of Consciousness. The Rishis says the very purpose of Human's life is to realize this Consciousness.

Most of the Puranas abound in lengthy narratives of legends glorifying a particular god or deity, delineating his or her incarnations, descriptions of holy places of pilgrimage (Tirtha), vows or observances (Vrata), acts of charity (Dana), and the like, with some shorter or longer references to the process of creation, the genealogy of the gods, demons and kings, stories of Rishis, as well as occasional statements on the foundations of politics, and the arrangement of the continents of the world as parts of the cosmos.

   Thus, the Puranas form a general encyclopaedia of popular thought on religion and philosophy. But the Bhagavata and the Vishnu Puranas are a great exception to this rule and they constitute a really splendid literature on a very lofty philosophy and mysticism.  

 In Vedic tradition, however everything is centered around  the main Trinity Gods Brahma, Vishnu and Shiva  are the symbolism of the Mind, Intellect and Awareness.  Brahma is the creator God, Vishnu the sustainer and Shiva the destroyer. All the three originate from the Supreme Para-Brahmam, the Pure-unconditional Consciousness.