In Hinduism and other Indian religions, a sacred syllable considered the greatest of all mantra s.
The syllable om is composed of the three sounds a-u-m (in the Sanskrit language , the vowels a and u join to become o ), which represent three important triads: earth, atmosphere, and heaven; the major Hindu gods, Brahma , Vishnu , and Shiva ; and the sacred Vedic scriptures, Rig, Yajur, and Sama (see Vedic religion ). Thus om mystically embodies the essence of the universe. It is uttered at the beginning and end of Hindu prayers, chants, and meditation and is also freely used in Buddhist and Jain rituals.