The traditional Indian knowledge system has given rise to several branches of knowledge that are now collectively known as the Indian knowledge system. As per the classical concept, IKS is divided into 18 sources of knowledge, Ashtadasavidhyasthanani. Of these Four Vedas are considered as pramanas or primary sources of knowledge. Another ten namely Six Vedangas and Four Upangas are focused on helping the student to learn the knowledge said in Vedas. As per the Yajnavalkya smriti (1.3) all these three groups combined form 14 branches of spiritual knowledge or Chaturdasavidhyasthana . The four Upaveda are applied science, these, combined with 14 spiritual knowledge system form the 18 broad subjects of IKS.

Four Vedas: Rigveda Yajurveda Samaveda Athervaveda

Six Vedangas: Siksha (phonetics), Vyakarana (grammer and linguistics), Chandas (prosody), Niruktha Etymology), Jyotisha (Astrology and Astronomy) and Kalpa (rituals and its practices)

Four Upangas: Nyaya, Mimamsa, Itihasa-Purana, and Dharmasasthra

Four Upavedas: Ayurveda, Dhanurveda, Gandharvaveda, Sthapatyaveda/Arthasasthra