Acharya Prashant explains that Vedanta is the culmination of the philosophy of the Vedas, serving as the root for all philosophical systems and spiritual streams in India. He clarifies that Vedanta is not a belief system or a religion but is exploratory in nature, carrying no dogmas or fables. It operates with extreme rigor, questioning the very nature of the 'I' or the experiencer rather than relying on subjective experiences. He notes that the Upanishads, which are the cornerstone of Vedanta, were composed over a vast stretch of time, with the oldest dating back approximately 4,000 years.