The meaning of “Om,” both as a word and its tie to yoga is an extremely commonly asked question. The symbol, pictured above, is universally associated with yoga, but many people do not know why. Om, which is frequently chanted at the beginning and/or end of a yoga class, is said to be the “sound of the universe.”
Ancient yogis believed what modern science is only now telling us – that the entire universe is always in a state of movement. Everything that exists, each one of us, each tree, the earth – all creates a vibration that was acknowledged by ancient people with the sound of Om. It is believed that chanting Om, pronounced as a long A-U-M, allows people to recognize ourselves as part of the movement of the universe as a whole. Om symbolizes the idea that we are all one – each individual, our breath, the sun, the moon, the tides, and back to our beating heart – we are all one.
According to ancient scripts Om is the sound of life. It is the infinite vibration that shimmers through the Universe, providing life and sustenance to everything.Om is the beginning and will continue till the end; the one constant that unites all of creation at its deepest level.
Tibetan scholar Lama Govinda wrote that Om expresses and leads to the “experience of the infinite within us.” In yoga, the four parts of Om are often reflected upon. As mentioned above, though commonly spelled Om, the mantra actually consists of three letters, a, u, and m. A represents our waking state, which is also the subjective consciousness of the outer world; U is the dreaming state – our inner world of thoughts, memories, etc; and M is the dreamless state of deep sleep and the experience of ultimate unity with the universe.
By contemplating the meaning of each of these letters as we chant them as one long “Auuu-ooh-mmm”, we are led through three states of our consciousness. After the chant, the vibration becomes silence. This silence is the crown of the mantra; it is described in the Maitri Upanishad as “tranquil, fearless, blissful, satisfied, immovable, immortal, unshaken, enduring.”
*Much of this info is taken from YogaJournal.com