According to Patanjali's Yoga Sutras, smriti is one of the five vritti, which are the thoughts or fluctuations of the mind that affects one's consciousness. The other four vritti are pramana, viparyaya, vikalpa and nidra.
Smriti literature can be classified as follows:
- Vedangas: essential to understanding the essence of the Vedas
- Upavedas: the arts and sciences
- Upangas: knowledge
- Darsanas: windows to truth and the path to liberation
The famous Hindu epics, "Ramayana," "Mahabharata" and the Bhagavad Gita, all belong to smriti literature.