Prasthanatrayi

Prasthanatrayi (Sanskrit: प्रस्थानत्रयी, IAST: Prasthānatrayī), literally, three sources, refers to the three canonical texts of Hindu philosophy, especially of the Vedanta schools. It consists of:

1. The Upanishads, known as Upadesha prasthana (injunctive texts), and the Śruti prasthāna (the starting point of revelation)
2. The Brahma Sutras, known as Nyaya prasthana or Yukti prasthana (logical text)
3. The Bhagavad Gita, known as Sadhana prasthana (practical text), and the Smriti prasthāna (the starting point of remembered tradition)

The Upanishads consist of twelve or thirteen major texts, with a total of 108 texts. The Bhagavad Gītā is part of the Mahabhārata.The Brahma Sūtras (also known as the Vedānta Sūtras), systematize the doctrines taught in the Upanishads and the Gītā.

All the founders of the three major schools of Vedanta, viz, Adi Shankara, Ramanujacharya, and Madhva wrote bhāṣyas (commentaries) on these texts.