The Upanishads are the most sacred late Vedic and post-Vedic Sanskrit texts which are considered to contain the ultimate truth and the knowledge that leads to spiritual emancipation.

These are the philosophical-religious texts of Hinduism which develop and explain the fundamental tenets of the religion. They are utterances of seers who spoke out of the fullness of their illumined experience.

Upanishad is derived from upa (near), ni (down) and sad (to sit). Hence, the term implicit the pupils, intent on learning, sitting near the teacher to acquire knowledge and truth. While there are over 200 Upanishads, the traditional number is 108. Of these, only 10 are the principal Upanishads: Isha, Kena, Katha, Prashna, Mundaka, Mandukya, Taittiriya, Aitareya, Chandogya and Brihadaranyaka.