The 
Vedas (
/ˈveɪdəz/,
[4] IAST: 
veda, 
Sanskrit: वेदः, 
lit. 'knowledge') are a large body of 
religious texts originating in 
ancient India. Composed in 
Vedic Sanskrit, the texts constitute the oldest layer of 
Sanskrit literature and the oldest 
scriptures of 
Hinduism.
[5][6][7]
There are four Vedas: the 
Rigveda, the 
Yajurveda, the 
Samaveda and the 
Atharvaveda.
[8][9] Each Veda has four subdivisions – the 
Samhitas (
mantras and 
benedictions), the 
Aranyakas (text on rituals, ceremonies, sacrifices and symbolic-sacrifices), the 
Brahmanas (commentaries on rituals, ceremonies and sacrifices), and the 
Upanishads (texts discussing 
meditation, philosophy and spiritual knowledge).
[8][10][11] Some scholars add a fifth category – the 
Upasanas (worship).
[12][13] The texts of the Upanishads discuss ideas akin to the heterodox 
sramana-traditions.
[14]
Vedas are 
śruti ("what is heard"),
[15] distinguishing them from other religious texts, which are called 
smṛti ("what is remembered"). Hindus consider the Vedas to be 
apauruṣeya, which means "not of a man, superhuman"
[16] and "impersonal, authorless,"
[17][18][19] revelations of sacred sounds and texts heard by ancient 
sages after intense meditation.
[20][21]
The Vedas have been orally transmitted since the 2nd millennium BCE with the help of elaborate mnemonic techniques.[22][23][24] The mantras, the oldest part of the Vedas, are recited in the modern age for their phonology rather than the semantics, and are considered to be "primordial rhythms of creation", preceding the forms to which they refer.[25] By reciting them the cosmos is regenerated, "by enlivening and nourishing the forms of creation at their base."[25]
The various 
Indian philosophies and 
Hindu denominations have taken differing positions on the Vedas; schools of Indian philosophy which acknowledge the primal  authority of the Vedas are classified as "orthodox" (
āstika).
[note 2] Other 
śramaṇa traditions, such as 
Charvaka, 
Ajivika, 
Buddhism and 
Jainism, which did not regard the Vedas as authorities, are referred to as "heterodox" or "non-orthodox" (
nāstika) schools.
[14][26]