What is a Mantra?
I have mentioned mantras, perhaps a brief description of what they are, and why they are used, is in order. A mantra is a sound, syllable, word, or phrase that is capable of transformation. There are many mantras, I will offer what is probably the most commonly recognized by non Buddhists.
This 6 syllable mantra is associated with Avalokiteshvara, the Bodhisattava of Compassion. The meanings for each syllable are quite intricate. If you would like an excellent chart on the various implied meanings of each syllable, wikipedia has on included in this article http://en.wikipedia.org/wiki/Om_mani_padme_hum