The Vedas are a large body of texts originating in ancient India. Composed in Vedic Sanskrit, the texts constitute the oldest layer of Sanskrit literature and the oldest scriptures of Hinduism.The Vedas are apauruṣeya («not of human agency»). They are supposed to have been directly revealed, and thus are called śruti («what is heard»), distinguishing them from other religious texts, which are called smṛti («what is remembered»).
The Vedic texts or śruti are organized around four canonical collections of metrical material known as Saṃhitās, of which the first three are related to the performance of yajna (sacrifice) in historical Vedic religion:
1. The Rigveda, containing hymns to be recited by the hotṛ;
2. The Yajurveda, containing formulas to be recited by the adhvaryu or officiating priest;
3. The Samaveda, containing formulas to be sung by the udgātṛ.
4. The fourth is the Atharvaveda, a collection of spells and incantations, apotropaic charms and speculative hymns.
