The Upanishads are early philosophical texts of the Hindu religion and contain within them the tenets upon which the central philosophical concepts of the religion are based. The Upanishads offer profound and timeless philosophical and spiritual meditations on divine inspiration, the creation of the world, the nature of reality, and the unity of all existence.
Along with the Bhagavad Gita and the Brahmasutra, the Upanishads provide a foundation for the several later schools of Vedanta.