We have to first understand the difference between Shruti & Smriti ?
Shruti(श्रुति) means that which has been heard or communicated by a tradition with no starting point. Vedas & Upanishads are Shruti Scriptures
Smriti(स्मृति ) means which is remembered or author by an individual ( produced by human intellect ).
Major Smriti scriptures are: Vedang(वेदाङ्ग), Upaveda(उपवेद), Upang(उपांग), Dharma-Sutra/Shstra(धर्मसूत्र), Purans(पुराण), Ramayana, Mahabharata e.t.c
What are Vedas ?
Vedas are Shruti scripture. It is believed that knowledge of Vedas are trasnfered to Rishi/Sages directly by the Brahman ( formless god ). therefore Vedas are called apauruṣeya (अपौरुषेय ), which means “not of a man, superhuman” and “impersonal, authorless”. Sages were द्रष्टा (seers) rather than author of Veda.
There are four Vedas : Rigveda(ऋग्वेद), Samaveda(सामवेद), Yajurveda(यजुर्वेद) & Athrvaveda(अथर्ववेद).
Each Veda has been subclassified into four major text types
- Samhitas (mantras )
- Aranyakas (text on rituals, ceremonies, sacrifices )
- Brahmanas (commentaries on rituals, ceremonies and sacrifices)
- Upanishads (texts on philosophy and spiritual knowledge)
What are Upanishads ?
Upanishads is created to give the self knowledge ( Atman-Gyana), therefore Upanishads are main texts for Vedanta philosophy.
Vedanta is philosophy which believes that Liberation can be attained by Knowing the Atman as the source and creator of this physical body and world.
The main purpose Upanishads were created is to negate the individual’s identification with physical body. Upanishads says that world has no real purpose, as it is creation of Maya and is falsely believed as real by Brahman. It is similar to a dreamer, who creates a dream world and see himself as a body in the dream and think dream world as real.
Upanishads are part of Vedas. Upanishads originated from each branch of Veda
What are Puranas ?
Puranas are part of Smriti texts, there are 18 Maha Puranas (Great Puranas) and 18 Upa Puranas (Minor Puranas) . Their main purpose of Puranas was to spread Bhakti & devotion among masses.