Handed down since ancient times by religious seers who had attained self-realization by chanting them, mantras are words or syllables in Sanskrit which when repeated in meditation helps you transcend into a higher state of consciousness. As sound energies that have always existed the universe, they cannot be created or destroyed and command the power to heal you physically & spiritually. At the very basic level mantras help you to concentrate in meditation. And once you enter its auspicious circle, the mind instantly gets focussed and you discover a new realm of peace and tranquility.
The original of all mantras, Om, is the root of all sounds, thus letters and therefore of all language and thought. The "O" is generated deep within the body, from inside the navel, and slowly brought upward joining with the "m" which then resonates through the entire head. Chanting Om in a whisper correctly for twenty minutes relaxes every atom in of every cell of your body.
A mala (garland of Sandal or Rudraksha) is often used in accompaniment. It has one hundred and eight beads plus the larger `meru' beads. Holding it in the right hand, start at the meru and roll the beads along one by one between your thumb and third fingers while repeating your mantra. When you reach the meru, roll the mala in the opposite direction. Do not cross over the meru bead.