Vedanta (meaning literally the end of the Vedas) is a branch of Hindu philosophy. It is not based on analysis or empty philosophy, but rather is a system of Jnana Yoga that attempts to aid the individual to enlightenment. It relies on the Upanishads, which are known as Vedanta due to their containing the end and fundamental essence of all the Vedas, and some of the earlier Aranyakas. Three branches of Vedanta exist, each branch choosing to interpret the codified scriptures in its own way. The most important and popular Vedantic branch is the Advaita (a- not, dwaita- two; meaning non-duality). This branch was realized by the Hindu philosopher Shankara (c. 800 AD).
Vedanta in General
While the traditional Vedic 'karma kanda' (ritualistic components of religion) continued to be practiced as meditative and propitiatory rites gearing society (through the Brahmins) to Self-knowledge, more jnana (knowledge/discrimination) centered understandings began to emerge, mystical streams of Vedic religion that focused on meditation, self-discipline and spiritual connectivity rather than more practical aspects of religion like rituals and rites. The more abstruse Vedanta (meaning literally the end of the Vedas) is the essence of the Vedas, encapsulated in the Upanishads which are commentaries on the four original books (Rig Veda, Yajur Veda, Sama Veda and Atharva Veda).
Their systematization into one coherent treatise was undertaken by Badarayana, in a work called the Vedanta Sutra, also known as Brahma Sutra, that appeared around the time of Christ.
The cryptic way in which the aphorisms of the Vedanta Sutras are presented leaves the door open for a few interpretations. This led to the formation of three Vedanta schools. Each of these interprets the texts in its own way and has produced its own series of sub-commentaries - all claiming to be faithful to the original. But, consistent throughout Vedanta is the authoritative declaration that ritual is to be eschewed in favor of intuitional questing for truth, for meditation governed by a loving morality, secure in the knowledge that infinite bliss does await her/him who seeks beyond the mere body and mind for it. Practically all sects of Hinduism today have directly or indirectly been affected by the thought systems developed by these thinkers. The survival of Hinduism, to a great extent, was aided by the formation of the coherent and logically advanced systems of Vedanta.
Vedanta has influenced modern science enormously. Schrödinger was a Vedantist, and he claimed to have been inspired by it in his discovery of quantum theory. According to his biographer Walter Moore, there is a clear continuity between Schrödinger’s understanding of Vedānta and his research: "The unity and continuity of Vedanta are reflected in the unity and continuity of wave mechanics. In 1925, the world view of physics was a model of a great machine composed of separable interacting material particles. During the next few years, Schrödinger and Heisenberg and their followers created a universe based on superimposed inseparable waves of probability amplitudes. This new view would be entirely consistent with the Vedantic concept of All in One."
There are three main Vedanta schools: Advaita Vedanta, Vishishtadvaita Vedanta, and Dvaita.
Other than Shri Adishankara, Shri Ramanuja and Shri Madhva (the founders of each of the three main Vedantic divisions), other important Vedantins include: Ramakrishna Paramahansa, Swami Vivekananda, Sri Aurobindo, Sri Ramana Maharshi, Nisargadatta Maharaj, Swami Chinmayananda and the American Ram Dass. The American Buddhist philosopher Ken Wilber's thinking is similar to and conversant with Advaita Vedanta.