Aum (ॐ) is a sacred sanskrit word and its primordal sound is called "Anahata Nada The "Unstruck Sound. It is the Holy Ghost of the Christian Faith. It is the verb and word of God as extolled by St John, the Apostle. “In the beginning was the Word, and the Word was with God, and the Word was God.… All things were made by him; and without him was not any thing made that was made.” —John 1:1–3.
In Hinduism is also referred as Onkara/Omkara and Pranav/Pranava. In the Upanishads is described as"the sacred sound, the Yes!, the Vedas, the Udgitha (song of the universe), the infinite, the all encompassing, the whole world, the truth, the ultimate reality, the finest essence, the cause of the Universe, the essence of life." (Courtesy of Wikipedia)
In different religions is known under different names. For example Christians & Jewish call it Amen (the Faithful), derived from the Hebrew tradition, in Ancient Egypt was known as Amin, which means faithful in Arabic, Buddhists call this sacred mantra Hum, and in the Sikhs call it the Shabd. If you would like to learn more Click here.
