From the wikipedia
"A mantra (Devanagari मन्त्र) is a religious or mystical syllable or poem, typically from the Sanskrit language. Their use varies according to the school and philosophy associated with the mantra. They are primarily used as spiritual conduits, words or vibrations that instill one-pointed concentration in the devotee. Other purposes have included religious ceremonies to accumulate wealth, avoid danger, or eliminate enemies. Mantras originated in the Vedic religion of India, later becoming an essential part of the Hindu tradition and a customary practice within Buddhism, Sikhism and Jainism. The use of mantras is now widespread throughout various spiritual movements which are based on, or off-shoots of, the practices in the earlier Eastern religions."