The Upanishads are a collection of sacred texts in Hinduism, and their authors are often unknown. They were written over a period of several centuries by different sages, philosophers, and scholars. Some of the well-known Upanishads include the Brihadaranyaka Upanishad, Chandogya Upanishad, Katha Upanishad, and Taittiriya Upanishad, among others.
