The Upanishads, a collection of ancient Indian texts, mark a pivotal transition in Hindu thought from ritualistic practices to profound philosophical inquiry. Composed between 800 BCE and 200 BCE, they form the concluding part of the Vedic corpus, focusing on metaphysical concepts like Brahman (ultimate reality), Atman (individual soul), and Moksha (liberation). Their teachings emphasize internal spiritual knowledge over external rituals, profoundly influencing Indian philosophy, spiritual practices, and culture. The Upanishads' impact extends beyond India, resonating with global philosophers and modern thinkers, shaping diverse spiritual and intellectual traditions worldwide.