Puranas are the compilation of an ancient Indian Genre of Hindu and Jaina Literature. Following the etymological meaning of the Puranas, ancient scholar Vayu depicted Puranas as "that which lives from ancient times". In a way the Puranas can be ascribed as the post Vedic texts narrating the history of Universe, from its creation to destruction, genealogies of kings, heroes and demigods with a detailed discussion of Hindu Cosmology and Philosophy. With the passage of time Puranas has attained the sanctity of a holy book to the Hindus.

Following Vayu, the other renowned scholars have also depicted the meaning of Puranas in their own way. Matsya described the Puranas as `containing the records of past events`. Originally, therefore, the term Puranas signified `ancient tale` or `old narrative` in the Brahmana literature, as compared with itihasa and narashamsi. After a long period of time the Puranas became associated with the class of literature. Although in the ancient period there was no separate genre of Purana literature, the Puranas in the form of legendary lore existed even prior to the revelation of the Vedas.

Apart from the definitions provided by the ancient scholars, the allusions of the legendary lore of the Puranas are also available in the antique texts of ancient Indian Literature. References in the Artharva Veda imply that the Puranas had assumed some independent form of composition, which had a unique essence than the other contemporary literary texts. But it is not clearly mentioned in Atharva Veda, whether at that time the Puranas meant actual books. The Chhandogya-Upanishad, however, shows that a definite work was intended by the term, but it is only the Sutras that reveal the existence of the real Puranas.

However the scholars have made a prolonged research about the contents and the subject with which the Puranas deals. According to those scholars, both Itihasa and Purana denoted history and both are mentioned together in Vedic literature, sometimes as separate and sometimes as compound words. But whatever is the process of compilation both the Puranas and Itihasa are almost always associated with gathas, narashamsi, vakovakyas, etc., which were all subjects of study in those days. In the later Vedic Age, Itihasa overshadowed the legendary lore of Purana, but gradually the latter asserted itself with its uniqueness in composition and construction.

Puranas being uniquely different from the other contemporary literary texts, several researches have been made to determine the characteristics of the Puranas. Many renowned ancient texts however have the references of the characteristics of the Puranas. However the ancient recorded definition and characteristics of Puranas has been provided by Amarasimha. The classical definition as provided by Amarasimha in the 5th century AD is also found in some Puranas. According to Amarasimha, the Puranas have five basic characteristics or panchalakshana. These are Sarga (creation), Pratisarga (dissolution and recreation), Vamsha (divine genealogies), Manvantara (ages of Manus), and Vamshanucharita (genealogies of kings). A variant has world geography in place of genealogies of kings.

But the characteristics of Puranas as described by Amarasimha hardly is in complete agreement with the existing Puranas. Some texts contain much more than these five characteristics, while the other text hardly discusses with panchalakshana rather these texts deals with some other materials. According to the latest researches Panchalakshana covers a trivial part (about 1/40) of the extant Puranas.

Following the later researches of the characteristics of Puranas, it has been made clear that the Puranas does not solely endeavor to provide religious instruction, nor the sectarian purpose was the primary aim of its composition. Description of gifts, religious observances, sacred places, etc., have now become the concerning subjects of the bulk of the Puranas. As a result nowadays the Panchalakshana definition appears merely theoretical.

The later composers however solved this difficulty by stating that the panchalakshana definition applied only to the Upa Purana (minor Purana), and that the Maha Purana (major Purana) should have ten characteristics or dashalakshana. According to them the dashalakshana includes several additional topics like vritti (means of livelihood), raksha (incarnation of gods), mukti (final emancipation), hetn (jiva, unmanifest) and apashraya (Brahman). According to the research scholars these characteristics, however, missed several basic features of the Puranas, such as glorification of Brahma, Vishnu, Surya and Rudra, termination and preservation of the world, dharma (righteous conduct), artha (economics and polity), kama (erotic) and Moksha (emancipation). But in spite of providing a comprehensive description of the Puranas , the definition of Puranas given by Matsya does not cover the entire ground traversed by the Puranas.

The Pitrana tradition, like that of Mahabharata, has been dynamic. Hence the texts of the Pitrana tradition have been subjected to numerous revisions. In the courses of several revisions many additions, omissions and modifications have been made in those texts. Shifted from dynamism, antiquity is the only feature that can characterize the Puranas. According to the observation of Haraprasad Shastri "Anything old may be the subject of a Puranas," and it covers all the aspects of life.