Brahman is the ultimate reality, the infinite, eternal, and all-pervading consciousness that is the ground of all existence in Hindu philosophy. It is described in the Upanishads as "Satyam Jnanam Anantam" (Truth, Knowledge, Infinite). Brahman is not a personal god but the formless, attributeless (Nirguna) absolute from which everything emanates and to which everything returns. However, when Brahman manifests with attributes (Saguna Brahman), it is worshipped as Ishvara — taking forms such as Brahma (creator), Vishnu (preserver), and Shiva (transformer). The Mandukya Upanishad identifies Brahman with the syllable Om. The relationship between individual Atman and universal Brahman is the central inquiry of Vedanta philosophy, with different schools offering different interpretations (identity, qualified identity, or eternal distinction).