“The Upanishads are also called the Vedanta. The literary meaning of Vedanta is ‘the end of the Vedas.’ But the spiritual meaning of Vedanta is ‘the cream of the Vedas, the pick of the inner lore, the aim, the goal of the inner life. In the Upanishads the spiritual meanings of the Vedic texts are brought out and emphasized in their own right.
According to our Indian tradition, there were once one thousand one hundred and eighty Upanishads. Each came from one branch, shakha, of the Vedas. Out of these, two hundred Upanishads made their proper appearance, and out of these two hundred, one hundred and eight Upanishads are now traceable.
The thirteen principal Upanishads are: Isha, Katha, Kena, Prasna, Mundaka, Mandukya, Chandogya, Brhadaranyaka, Taittiriya, Aitareya, Svetasvatara, Kaivalya, and Maitri
The message of the Upanishads is the life divine, the life of transformed humanity, and the life of an illumined earth-consciousness. The Upanishads tell us that the renunciation of desire-life is the fulfilling enjoyment of world-existence. This renunciation is neither self-denial nor self-rejection. This renunciation demands the transcendence of ego to breathe in freely the life-energy of the soul and yet to live a dynamic and active life in the world where one can achieve Infinity’s Height, Eternity’s Delight, and Immortality’s Light.”
Source: Sri Chinmoy