OM or AUM signifies the essence of the ultimate reality, consciousness or aatman... More broadly, it is a syllable that is chanted either independently or before a spiritual recitation in Hinduism, Buddhism, and Jainism.. The meaning and connotations of Om may vary between the diverse schools within and across the various traditions.. It is also part of the iconography found in ancient and medieval era manuscripts, temples, monasteries and spiritual retreats in Hinduism, Buddhism, Jainism and Si