Vedas

The Vedas (Sanskrit वेदाः véda, "knowledge") 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.

The individual verses contained in these compilations are known as mantras. Some selected Vedic mantras are still recited at prayers, religious functions and other auspicious occasions in contemporary Hinduism.

The various Indian philosophies and sects have taken differing positions on the Vedas. Schools of Indian philosophy which cite the Vedas as their scriptural authority are classified as "orthodox" (āstika). Other traditions, notably Buddhism and Jainism, which did not regard the Vedas as authorities are referred to by traditional Hindu texts as "heterodox" or "non-orthodox" (nāstika) schools. In addition to Buddhism and Jainism, Sikhism and Brahmoism, many non-Brahmin Hindus in South India do not accept the authority of the Vedas. Certain South Indian Brahmin communities such as Iyengars consider the Tamil Divya Prabandham or writing of the Alvar saints as equivalent to the Vedas.