Om

''Om'' (or ''Aum'') (; , ISO 15919: ''Ōṁ'') is a polysemous symbol representing a sacred sound, syllable, mantra, and invocation in Hinduism. Its written form is the most important symbol in the Hindu religion. It is the essence of the supreme Absolute, consciousness, ''Ātman,'' ''Brahman,'' or the cosmic world. In Indic traditions, ''Om'' serves as a sonic representation of the divine, a standard of Vedic authority and a central aspect of soteriological doctrines and practices. It is the basic tool for meditation in the yogic path to liberation. The syllable is often found at the beginning and the end of chapters in the Vedas, the Upanishads, and other Hindu texts. It is described as goal of all Vedas.

''Om'' emerged in the Vedic corpus and is said to be an encapsulated form of ''Samavedic'' chants or songs. It is a sacred spiritual incantation made before and during the recitation of spiritual texts, during ''puja'' and private prayers, in ceremonies of rites of passage (''samskara'') such as weddings, and during meditative and spiritual activities such as Pranava yoga. It is part of the iconography found in ancient and medieval era manuscripts, temples, monasteries, and spiritual retreats in Hinduism, Buddhism, Jainism, and Sikhism. As a syllable, it is often chanted either independently or before a spiritual recitation and during meditation in Hinduism, Buddhism, and Jainism.

The syllable ''Om'' is also referred to as Onkara (Omkara) and Pranava among many other names. Provided by Wikipedia