Adi Shankara, also called Adi Shankaracharya, was an Indian Vedic scholar and teacher (acharya) of Advaita Vedanta. Reliable information on Shankara's actual life is scanty, and his true impact lies in his "iconic representation of Hindu religion and culture," despite the fact that most Hindus do not adhere to Advaita Vedanta. He is seen as "the one who restored the Hindu dharma against the attacks of the Buddhists and in the process helped to drive Buddhism out of India." Tradition also portrays him as the one who reconciled the various sects with the introduction of the Pañcāyatana form of worship, the simultaneous worship of five deities – Ganesha, Surya, Vishnu, Shiva and Devi, arguing that all deities were but different forms of the one Brahman, the invisible Supreme Being.

Advaita Vedanta is a Hindu-tradition of textual exegesis and philosophy and a Hindu sādhanā, a path of spiritual discipline and experience. In a narrow sense it refers to the scholarly tradition belonging to the orthodox Hindu Vedānta tradition, with works written in Sanskrit, as exemplified by the Vedic scholar and teacher (acharya) Adi Shankara ; in a broader sense it refers to a popular medieval and modern syncretic tradition, blending Vedānta with Yoga and other traditions and producing works in vernacular.