We believe that Vedas were not written, but rather a compilation of ‘what was heard’, hence they are called ‘Shruti’. 

These are the most sacred, ancient, and authoritative texts in Hinduism, with all the schools accepting their authority. Shruti references are treated with great reverence and are considered the ultimate decision in any discussion. 

Given the importance given to it, let’s understand what makes up Shruti. 

As we all know, there are 4 Vedas, Rigveda, Yajurveda, Samveda, Atharvaveda, with Yajurveda having two separate versions, Krishna-Yajurveda, and Shukla-Yajurveda. 

Each of the 5 Vedas has its own Samhita (Mantras), Brahmana, Aranyaka (ritual part), and Upanishads (Knowledge part), together they are called Shruti. 

As Upanishads are arranged towards the end of Veda, they are called ‘Vedanta’ (i.e. last section of Vedas). 

Each of the 108 Upanishads is part of one of these 5 Vedas. For example, the 10 Mukhya Upanishads:

  1. Isha and Brihadaranyaka are part of Shukla Yajurveda 
  2. Katha and Taittariya are part of Krishna Yajurveda
  3. Mundaka, Mandukya, Prashna are part of Athervaveda 
  4. Chandogya and Kena are part of Samveda
  5. Aitareya Upanishad is from Rig Veda. 

Vedas also have Vedangas (वेदाङ्ग), which is supporting literature on how to read, recite Vedas and when to perform different rituals, etc.

  1. Shiksha – focusing on pronunciation
  2. Kalpa – Specifying common procedures for rituals, also birth, life events, and death rituals, also called as Sutras. 
  3. Vyakaran – Grammer of Vedic mantras
  4. Nirukta – Focused on describing ancients words
  5. Chandas – Focused on poetic meters
  6. Jyotishya – Auspicious time, and timekeeping in general. 

Vedangas while being associated with Vedas, are NOT considered Shruti. 

Finally, Bhagavad Gita, even though part of Itihasa literature, is considered as Shruti for multiple reasons. One, it is a summary of all the Vedic knowledge. Second, it’s told by Shri Krishna himself. Finally, it is ‘what was heard’ by Vyasa and Sanjay, during Krishna-Arjun dialog during the Kurukshetra war. 

This way, 5 Vedas, with their, Samhita, Brahmana, Aranyaka, Upanishads literature, along with Bhagavad Gita forms Shruti.