'OM' - Aum (also Om or Ohm, ) is the most sacred syllable in Hinduism, symbolizing the infinite Brahman and the entire Universe. This syllable is sometimes called the 'Udgitha' or 'pranava mantra' (primordial mantra), because it is considered by Hindus to be the primal sound, and because most mantras begin with it. It first appeared prominently in the Vedic Tradition. As a seed syllable (bija), it is also considered holy in Esoteric Buddhism.The symbol Aum (also called Pranava), is the most sacred symbol in Hinduism. Volumes have been written[name a specific person/group] in Sanskrit illustrating the significance of this mystic symbol. Although this symbol is mentioned in all the Upanishads and in all Hindu scriptures, it is especially elaborated upon in the Taittiriya, Chandogya and Mundaka Upanishads. From the Katha Upanishad (- I, ii, 15-17): The goal, which all Vedas declare, which all austerities aim at, and which humans desire when they live a life of continence, I will tell you briefly it is Aum. The syllable Aum is indeed Brahman. This syllable Aum is the highest. Whosoever knows this symbol obtains all that he desires. This is the best support; this is the highest support. Whosoever knows this support is adored in the world of Brahman