” A ” signifies the beginning of the universe.
U signifies the life period of universe
and M signifies the destruction of the Universe.
Hence Om is the only word which notifies the three main work of God that is creation, operation and destruction of srishti (Universe). This represents the three first forms of God viz. are Brahmaa (creator), Vishnu (operator) and the destructor (The Shiva).
Most of the mantra in Hinduism start with the word AUM, because AUM is the consciousness and the other words in a mantra are Nature or Prakriti. AUM in itself is a complete Mantra and its chanting is sacred and brings enlightenment. It is truely called MAHA MANTRA.
It does not belong to any language…it is primodal vibration of the consciousness which created the universe…Aum does not belong to any religion.
AUM has four steps A…U….M and the last one silent
A = Physical plane , wake-state of mind, beginning,Brahmaa, Raj
U = Astral Plane, dream state of mind, Manifestation, Vishnu, Sat
M = Causal Plane, dream-less state , Destruction,Rudra,Tam
Fourth unspoken sound = Turiya, beyond universe, Enlightened state
AUM is a great mantra. It is a Sagun Mantra, Nirgun Mantra and Beeja Mantra alll in One
Recitation of Aum brings peace and happiness, spiritual progress, intelligence siddhis and finally enlightenment