The term ‘Vedanta’ refers to the Upanishads and their teachings as well as to the traditions inspired by them, which follow from them. The source text of Vedanta is Badarayana’s Brahma Sutra, also called the Vedanta Sutra and Uttara Mimamsa Sutra. This text reconciles all apparent contradictions in the Upanishads and clealry lays down the essential principle of Vedanta, namely the unity of Atman (individual soul) with Brahman (the Supreme Soul)
Indeed, the Brahma Sutra is an investigation into Brahman, and it begins thus: ‘Now an investigation into Brahman’ (athato brahma-jijnasa).
A number of schools developed within the Vedanta tradition, whose founders and chief exponents wrote commentaries on the Brahma Sutras. Other texts were also the subject of exegetical commentary, most notably the Principal Upanishads and the Bhagavad Gita. This group of texts — the Brahma Sutra, the Upanisads and the Gita — forms the ‘triple basis’ of Vedanta commentarial tradition, and are known in Sanskrit collectively as the Prasthanatraya. The most important Vedanta traditions are Advaita (‘Non-Dualist’) Vedanta of Shri Shankaracharya, Visistadvaita (‘Qualified Non- Dualist’) Vedanta of Shri Ramanuja and Dvaita (‘Dualist’) Vedanta of Shri Madhvacharya. Out of these three, Advaita Vedanta has found the most universal acceptance.