Mantra means a sound. Today, modern science sees the whole existence as a vibration. Where there is a vibration, there is bound to be a sound. So that means, the whole existence is a kind of sound, or a complex amalgamation of sounds – the whole existence is an amalgamation of multiple mantras. Of these, a few mantras or a few sounds have been identified, which could be like keys. If you use them in a certain way, they become a key to open up a different dimension of life and experience within you.