Hindus consider the Vedas to be apauruṣeya, which means "not of a man, superhuman"[17] and "impersonal, authorless",[18][19][20] revelations of sacred sounds and texts heard by ancient sages after intense meditation.

[23][24][25] 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.

[note 2] However, śramaṇa traditions, such as Charvaka, Ajivika, Buddhism, and Jainism, which did not regard the Vedas as authoritative, are referred to as "heterodox" or "non-orthodox" (nāstika) schools.

This is not to be confused with the homonymous 1st and 3rd person singular perfect tense véda, cognate to Greek (ϝ)οἶδα ((w)oida) "I know".

[46] The Brahmanas, Aranyakas, and Upanishads, among other things, interpret and discuss the Samhitas in philosophical and metaphorical ways to explore abstract concepts such as the Absolute (Brahman), and the soul or the self (Atman), introducing Vedanta philosophy, one of the major trends of later Hinduism.

Nevertheless, it is advisable to stick to the division adopted by Max Müller because it follows the Indian tradition, conveys the historical sequence fairly accurately, and underlies the current editions, translations, and monographs on Vedic literature.

Witzel makes special reference to the Near Eastern Mitanni material of the 14th century BCE, the only epigraphic record of Indo-Aryan contemporary to the Rigvedic period.

[23][65][66] The authoritative transmission[67] of the Vedas is by an oral tradition in a sampradaya from father to son or from teacher (guru) to student (shishya),[23][24][66][68][69] believed to be initiated by the Vedic rishis who heard the primordial sounds.

[70] Only this tradition, embodied by a living teacher, can teach the correct pronunciation of the sounds and explain hidden meanings, in a way the "dead and entombed manuscript" cannot do.

[67] Houben and Rath note that the Vedic textual tradition cannot simply be characterized as oral, "since it also depends significantly on a memory culture".

[80] Houben and Rath note that a strong "memory culture" existed in ancient India when texts were transmitted orally, before the advent of writing in the early first millennium CE.

[101] The Vedas, Vedic rituals and its ancillary sciences called the Vedangas, were part of the curriculum at ancient universities such as at Taxila, Nalanda and Vikramashila.

[109] Yaska and Sayana, reflecting an ancient understanding, state that the Veda can be interpreted in three ways, giving "the truth about gods, dharma and parabrahman.

[119] Mukherjee notes that the Rigveda, and Sayana's commentary, contain passages criticizing as fruitless mere recitation of the Ŗik (words) without understanding their inner meaning or essence, the knowledge of dharma and Parabrahman.

[131] Each of the four Vedas were shared by the numerous schools, but revised, interpolated and adapted locally, in and after the Vedic period, giving rise to various recensions of the text.

"[150] In terms of substance, the nature of hymns shift from praise of deities in early books to Nasadiya Sukta with questions such as, "what is the origin of the universe?, do even gods know the answer?

[note 22] There are similarities between the mythology, rituals and linguistics in Rigveda and those found in ancient central Asia, Iranian and Hindukush (Afghanistan) regions.

[158] The core text of the Yajurveda falls within the classical Mantra period of Vedic Sanskrit at the end of the 2nd millennium BCE – younger than the Rigveda, and roughly contemporary with the Atharvaveda, the Rigvedic Khilani, and the Sāmaveda.

[162] Unlike the Samaveda which is almost entirely based on Rigveda mantras and structured as songs, the Yajurveda samhitas are in prose, and they are different from earlier Vedic texts linguistically.

[166][167] The youngest layer of Yajurveda text is not related to rituals nor sacrifice, it includes the largest collection of primary Upanishads, influential to various schools of Hindu philosophy.

[176] The Samhita layer of the text likely represents a developing 2nd millennium BCE tradition of magico-religious rites to address superstitious anxiety, spells to remove maladies believed to be caused by demons, and herbs- and nature-derived potions as medicine.

[177][178] The text, states Kenneth Zysk, is one of oldest surviving record of the evolutionary practices in religious medicine and reveals the "earliest forms of folk healing of Indo-European antiquity".

The sixth through last hymns of the first chapter in Chandogya Brahmana are ritual celebrations on the birth of a child and wishes for health, wealth, and prosperity with a profusion of cows and artha.

"[189] The Upanishads intend to create a hierarchy of connected and dependent realities, evoking a sense of unity of "the separate elements of the world and of human experience [compressing] them into a single form.

[196] The six subjects of Vedanga are phonetics (Śikṣā), poetic meter (Chandas), grammar (Vyākaraṇa), etymology and linguistics (Nirukta), rituals and rites of passage (Kalpa), time keeping and astronomy (Jyotiṣa).

[196][203] Pariśiṣṭa "supplement, appendix" is the term applied to various ancillary works of Vedic literature, dealing mainly with details of ritual and elaborations of the texts logically and chronologically prior to them: the Samhitas, Brahmanas, Aranyakas and Sutras.

The Bhakti movement, and Gaudiya Vaishnavism in particular extended the term veda to include the Sanskrit Epics and Vaishnavite devotional texts such as the Pancharatra.

[224][225] The Puranic literature wove with the Bhakti movement in India, and both Dvaita and Advaita scholars have commented on the underlying Vedanta themes in the Maha Puranas.

[note 23] Other śramaṇa traditions, such as Charvaka, Ajivika, Buddhism and Jainism, which do not regard the Vedas as authorities, are referred to as "heterodox" or "non-orthodox" (nāstika) schools.

The Anandabhairava-tantra for example, states that "the wise man should not elect as his authority the word of the Vedas, which is full of impurity, produces but scanty and transitory fruits and is limited.