GREETINGS

Swamiji:

Dear Subha,

Om represents the Universe (prapancham, jagat).

Just as the sound (while chanting Om) manifests itself (from the latent yet meaningful state of silence), gradually develops, sustains and finally subsides into the silence that follows, the prapancham manifests itself from the serenity/tranquillity of the Eternal Energy (CHAITHANYAM), sustains and finally dissolve into serenity of the Eternal Energy.

To explain it further,

This universe is formed of forms and words. When the cosmic energy of the Supreme Power pulsates, fire and sound are generated due to the friction and they cause forms and words. OM is said to be the original primordial creative sound from which the entire universe has manifested.

So, Om is the sound of the supreme consciousness. When you chant OM, you actually take the name of God.

Hari Om!