Traditionally, there are 18 main puranas and 18 minor puranas, which contain over 400,000 verses. Puranas typically cover five signs, or topics.
- Genealogy of the gods, sages and kings
- Cosmic cycles
- Legends during the times of various kings
Some other puranas, like the "Bhagavata Purana," add five more characteristics, expanding the list to 10:
- Karmic links between the deities, sages, kings and living beings
- Tales about god(s)
- Finale or cessation
- Spiritual liberation (moksha)
The purpose of the puranas was to bring people closer to the gods. All of the purana texts are sectarian, dedicated to certain deities -- some to gods, some to goddesses. Puranas also served to give the common people access to and understanding of the essential teachings and complex yogic philosophies of the ancient Vedic texts.
Puranas are the most revered and pertinent texts in the Bhakti yoga tradition, where the devotional aspect of yoga is emphasized. This devotion is cultivated through the personification of the chosen deities in entertaining myths and stories.
The "Bhagavata Purana" describes Bhakti yoga and outlines all the steps of its practice. Another text, the "Linga Purana," covers the details about yama (disciplines), niyama (virtues) and pranayama(breathing techniques). Meanwhile, the "Vayu Purana" contains information about pratyahara (withdrawal of the senses), dharana (concentration) and dhyana (meditation).