The class of "Vedic texts" is aggregated around the four canonical Saṃhitās or Vedas proper (turīya), of which three (traya) are related to the performance of yajna (sacrifice) in historical (Iron Age) Vedic religion:
- the Rigveda, containing hymns to be recited by the hotṛ or chief priest;
- the Yajurveda, containing formulas to be recited by the adhvaryu or officiating priest;
- the Samaveda, containing formulas to be chanted by the udgātṛ.
According to Hindu tradition, the Vedas are apauruṣeya "not of human agency", are supposed to have been directly revealed, and thus are called śruti ("what is heard").. Vedic mantras are recited at Hindu prayers, religious functions and other auspicious occasions.
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 also does not accept the authority of the Vedas. 
Etymology and usage
As a noun, the word appears only in a single instance in the Rigveda, in RV 8.19.5, translated by Griffith as "ritual lore":
- yáḥ samídhā yá âhutī / yó védena dadâśa márto agnáye / yó námasā svadhvaráḥ
- "The mortal who hath ministered to Agni with oblation, fuel, ritual lore, and reverence, skilled in sacrifice."
Geldner's translation of the same passage has Wissen "knowledge". 
The noun is from Proto-Indo-European *u̯eidos, cognate to Greek (ϝ)εἶδος "aspect", "form". Not to be confused is the homonymous 1st and 3rd person singular perfect tense véda, cognate to Greek (ϝ)οἶδα (w)oida "I know". Root cognate are Greek ἰδέα, English wit, witness, wisdom, vision (the last from the Latin video, videre), German wissen ("to know", "knowledge"), Danish vide (to know) Norwegian viten ("knowledge"), Swedish veta ("to know"), Russian 'ведать/vedat' ("to know"), 'видеть/videt' ("to see"), Polish wiedza ("knowledge"), Latin video ("I see"), Czech vím ("I know") or vidím ("I see"), Slovak vedieť ("to know") or vidieť ("to see"), and Dutch weten ("to know").
In English, the term Veda is mostly used to refer to the Samhitas (collection of mantras, or chants) of the four canonical Vedas (Rigveda, Yajurveda, Samaveda and Atharvaveda). The adjective Vedic on the other hand has wide currency, and depending on whether the context is academic (Indological or Philological) or religious (contemporary Hinduism) may refer either to the corpus of Vedic Sanskrit texts or to Hindu tradition in general.The Sanskrit term veda as a common noun meaning "knowledge"", but can also be used to refer to fields of study unrelated to liturgy or ritual, e.g. in agada-veda "medical science", sasya-veda "science of agriculture" or sarpa-veda "science of snakes" (already found in the early Upanishads); durveda means "with evil knowledge, ignorant"
The Vedas are among the oldest sacred texts in the world dating from c. 1500-500BCE. Most Indologists agree that an oral tradition existed long before a literary tradition tentatively may have been set in (in one shakha, Kanva) from about the 1st century BCE; however it was again superseded by oral tradition until c. 1000 CE. Due to the ephemeral nature of the manuscript material (birch bark or palm leaves), surviving manuscripts rarely surpass an age of a few hundred years. The Benares Sanskrit University has a Rigveda manuscript of the mid-14th century, however, there are a number of older Veda manuscripts in Nepal belonging to the Vajasaneyi tradition that are dated from the 11th century onwards.
The Vedic period lasts for about a millennium, spanning the Late Bronze Age and the Iron Age. Gavin Flood sums up mainstream estimates, according to which the Rigveda was compiled from as early as 1500 BCE over a period of several centuries. The Vedic period reaches its peak only after the composition of the mantra texts, with the establishment of the various shakhas all over Northern India which annotated the mantra samhitas with Brahmana discussions of their meaning, and reaches its end in the age of Buddha and Panini and the rise of the Mahajanapadas (archaeologically, Northern Black Polished Ware). Michael Witzel gives a time span of c. 1500 BCE to c. 500-400 BCE. Witzel makes special reference to the Mitanni material of ca. 1400 BCE as the only epigraphic record of Indo-Aryan that may date to the Rigvedic period. However Mitanni Indo-Aryan is linguistically slightly older than the language of the Rigveda, and the comparison thus still does not allow for an absolute dating of any Vedic text. He gives 150 BCE (Patanjali) as a terminus ante quem for all Vedic Sanskrit literature, and 1200 BCE (the early Iron Age) as terminus post quem for the Atharvaveda.
 Categories of Vedic texts
The term "Vedic texts" is used in two distinct meanings:
- texts composed in Vedic Sanskrit during the Vedic period (Iron Age India)
- any text considered as "connected to the Vedas" or a "corollary of the Vedas"
 Vedic Sanskrit corpus
The corpus of Vedic Sanskrit texts includes:
- The Samhita (Sanskrit saṃhitā, "collection"), are collections of metric texts ("mantras"). There are four "Vedic" Samhitas: the Rig-Veda, Sama-Veda, Yajur-Veda, and Atharva-Veda, most of which are available in several recensions (śākhā). In some contexts, the term Veda is used to refer to these Samhitas. This is the oldest layer of Vedic texts, apart from the Rigvedic hymns, which were probably essentially complete by 1200 BC, dating to ca. the 12th to 10th centuries BC. The complete corpus of Vedic mantras as collected in Bloomfield's Vedic Concordance (1907) consists of some 89,000 padas (metric feet), of which 72,000 occur in the four Samhitas.
- The Brahmanas are prose texts that discuss, in technical fashion, the solemn sacrificial rituals as well as comment on their meaning and many connected themes. Each of the Brahmanas is associated with one of the Samhitas or its recensions. The Brahmanas may either form separate texts or can be partly integrated into the text of the Samhitas. They may also include the Aranyakas and Upanishads.
- The Aranyakas , "wilderness texts" or "forest treaties", were composed by people who meditated in the woods as recluses and are the third part of the Vedas. The texts contain discussions and interpretations of dangerous rituals (to be studied outside the settlement) and various sorts of additional materials. It is frequently read in secondary literature.
- some of the older Mukhya Upanishads (Bṛhadāraṇyaka, Chandogya, Kaṭha).
- certain Sutra literature, i.e. the Shrautasutras and the Grhyasutras.
The Shrauta Sutras, regarded as belonging to the smriti, are late Vedic in language and content, thus forming part of the Vedic Sanskrit corpus. The composition of the Shrauta and Grhya Sutras (ca. 6th century BC) marks the end of the Vedic period , and at the same time the beginning of the flourishing of the "circum-Vedic" scholarship of Vedanga, introducing the early flowering of classical Sanskrit literature in the Mauryan and Gupta periods.
While production of Brahmanas and Aranyakas ceases with the end of the Vedic period, there is a large number of Upanishads composed after the end of the Vedic period. While most of the ten mukhya Upanishads can be considered to date to the Vedic or Mahajanapada period, most of the 108 Upanishads of the full Muktika canon date to the Common Era.
The Brahmanas, Aranyakas, and Upanishads often interpret the polytheistic and ritualistic 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.
The Vedic Sanskrit corpus is the scope of A Vedic Word Concordance (Vaidika-Padānukrama-Koṣa) prepared from 1930 under Vishva Bandhu, and published in five volumes in 1935-1965. Its scope extends to about 400 texts, including the entire Vedic Sanskrit corpus besides some "sub-Vedic" texts.
- Volume I: Samhitas
- Volume II: Brahmanas and Aranyakas
- Volume III: Upanishads
- Volume IV: Vedangas
A revised edition, extending to about 1800 pages, was published in 1973-1976.
 Shruti literature
The latter group of texts is called shruti (Sanskrit: śruti; "the heard"). Since post-Vedic times it has been considered to be revealed wisdom, as distinct from other texts, collectively known as smriti (Sanskrit: smṛti; "the remembered"), that is texts that are considered to be of human origin. This indigenous system of categorization was adopted by Max Müller and, while it is subject to some debate, it is still widely used. As Axel Michaels explains:
These classifications are often not tenable for linguistic and formal reasons: There is not only one collection at any one time, but rather several handed down in separate Vedic schools; Upanişads ... are sometimes not to be distinguished from Āraṇyakas...; Brāhmaṇas contain older strata of language attributed to the Saṃhitās; there are various dialects and locally prominent traditions of the Vedic schools. 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."
The Upanishads are largely philosophical works in dialog form. They discuss questions of nature philosophy and the fate of the soul, and contain some mystic and spiritual interpretations of the Vedas. For long, they have been regarded as their putative end and essence, and are thus known as Vedānta ("the end of the Vedas"). Taken together, they are the basis of the Vedanta school.
Other texts such as the Bhagavad Gita or the Vedanta Sutras are considered shruti or "Vedic" by some Hindu denominations but not universally within Hinduism. The Bhakti movement, and Gaudiya Vaishnavism in particular extended the term to include the Sanskrit Epics and Vaishnavite devotional texts such as the Pancaratra.
 Vedic schools or recensions
Study of the extensive body of Vedic texts has been organized into a number of different schools or branches (Sanskrit śākhā, literally "branch" or "limb") each of which specialized in learning certain texts. Multiple recensions are known for each of the Vedas, and each Vedic text may have a number of schools associated with it. Elaborate methods for preserving the text were based on memorizing by heart instead of writing. Specific techniques for parsing and reciting the texts were used to assist in the memorization process. (See also: patha)
Prodigous energy was expended by ancient Indian culture in ensuring that these texts were transmitted from generation to generation with inordinate fidelity. For example, memorization of the sacred Vedas included up to eleven forms of recitation of the same text. The texts were subsequently "proof-read" by comparing the different recited versions. Forms of recitation included the jaṭā-pāṭha (literally "mesh recitation") in which every two adjacent words in the text were first recited in their original order, then repeated in the reverse order, and finally repeated again in the original order.
That these methods have been effective, is testified to by the preservation of the most ancient Indian religious text, the Ṛgveda (ca. 1500 BCE), as a single text, without any variant readings. Similar methods were used for memorizing mathematical texts, whose transmission remained exclusively oral until the end of the Vedic period (ca. 500 BCE).The Four Vedas
The Four Vedas
The canonical division of the Vedas is fourfold (turīya) viz.,
Of these, the first three were the principal original division, also called trayī, "the triple Vidyā", that is, "the triple sacred science" of reciting hymns (RV), performing sacrifices (YV), and chanting (SV). This triplicity is so introduced in the Brahmanas (ShB, ABr and others), but the Rigveda is the older work of the three from which the other two borrow, next to their own independent Yajus, sorcery and speculative mantras.
Thus, the Mantras are properly of three forms: 1. Ric, which are verses of praise in metre, and intended for loud recitation; 2. Yajus, which are in prose, and intended for recitation in lower voice at sacrifices; 3. Sāman, which are in metre, and intended for singing at the Soma ceremonies.
The Atharvaveda is the fourth Veda. Its status has occasionally been ambiguous, probably due to its use in sorcery and healing. However, it contains very old materials in early Vedic language. Manusmrti, which often speaks of the three Vedas, calling them trayam-brahma-sanātanam, "the triple eternal Veda". The Atharvaveda like the Rigveda, is a collection of original incantations, and other materials borrowing relatively little from the Rigveda. It has no direct relation to the solemn Shrauta sacrifices, except for the fact that the mostly silent Brahmán priest observes the procedures and uses Atharvaveda mantras to 'heal' it when mistakes have been made. Its recitation also produces long life, cures diseases, or effects the ruin of enemies.
Each of the four Vedas consists of the metrical Mantra or Samhita and the prose Brahmana part, giving discussions and directions for the detail of the ceremonies at which the Mantras were to be used and explanations of the legends connected with the Mantras and rituals. Both these portions are termed shruti (which tradition says to have been heard but not composed or written down by men). Each of the four Vedas seems to have passed to numerous Shakhas or schools, giving rise to various recensions of the text. They each have an Index or Anukramani, the principal work of this kind being the general Index or Sarvānukramaṇī.
The Rig-Veda Samhita is the oldest significant existent Indian text. It is a collection of 1,028 Vedic Sanskrit hymns and 10,600 verses in all, organized into ten books (Sanskrit: mandalas). The hymns are dedicated to Rigvedic deities.
The books were composed by poets from different priestly groups over a period of some 500 years, which Avari dates as 1400 BCE to 900 BCE, if not earlier According to Max Müller, based on internal evidence (philological and linguistic), the Rigveda was composed roughly between 1700–1100 BCE (the early Vedic period) in the Punjab (Sapta Sindhu) region of the Indian subcontinent. Michael Witzel believes that the Rig Veda must have been composed more or less in the period 1450-1350 BCE, in the Greater Panjab, before the onset of the Iron Age.
There are strong linguistic and cultural similarities between the Rigveda and the early Iranian Avesta, deriving from the Proto-Indo-Iranian times, often associated with the Andronovo culture; the earliest horse-drawn chariots were found at Andronovo sites in the Sintashta-Petrovka cultural area near the Ural mountains and date to ca. 2000 BCE.
The Yajur-Veda ("Veda of sacrificial formulas") consists of archaic prose mantras and also in part of verses borrowed and adapted from the Rig-Veda. Its purpose was practical, in that each mantra must accompany an action in sacrifice but, unlike the Sama-Veda, it was compiled to apply to all sacrificial rites, not merely the Soma offering. There are two major recensions of this Veda known as the "Black" and "White" Yajur-Veda. The origin and meaning of these designations are not very clear. The White Yajur-Veda contains only the verses and formulas (yajus) necessary for the sacrifice, while their discussion exist in a separate work, the Shatapatha Brahmana. It differs widely from the Black Yajurveda, which incorporates such discussions in the work itself, often immediately following the verses. Of the Black Yajurveda four major recensions survive (Maitrayani, Katha, Kapisthala-Katha, Taittiriya), all showing by and large the same arrangement, but differing in many other respects, notably in the individual discussion of the rituals but also in matters of phonology, accent, grammatical forms, syntax and choice of words.
The Sama-Veda (Sanskrit sāmaveda ) is the "Veda of melodies" or "Knowledge of melodies". The name of this Veda is from the Sanskrit word sāman which means a melody applied to metrical hymn or song of praise. It consists of 1549 stanzas, taken entirely (except 78) from the Rig-Veda. Like the Rigvedic stanzas in the Yajurveda, the Samans have been changed and adapted for use in singing. Some of the Rig-Veda verses are repeated more than once. Including repetitions, there are a total of 1875 verses numbered in the Sama-Veda recension translated by Griffith. Two major recensions remain today, the Kauthuma/Ranayaniya and the Jaiminiya.
Its purpose was liturgical and practical, to serve as a songbook for the "singer" priests who took part in the liturgy. A priest who sings hymns from the Sama-Veda during a ritual is called an udgātṛ, a word derived from the Sanskrit root ud-gai ("to sing" or "to chant"). A similar word in English might be "cantor". The styles of chanting are important to the liturgical use of the verses. The hymns were to be sung according to certain fixed melodies; hence the name of the collection.
The Artharva-Veda is the "Knowledge of the [atharvans] (and Angirasa)". The Artharva-Veda or Atharvangirasa is the text 'belonging to the Atharvan and Angirasa' poets. Apte defined an atharvan as a priest who worshipped fire and Soma. However, the etymology of Atharvan is unclear, but according to Mayrhofer it is related to Avesta athravan (āθrauuan); he denies any connection with fire priests. Atharvan was an ancient term for a certain Rishi even in the Rigveda. (The older secondary literature took them as priests who worshipped fire).
It was compiled around 900 BCE, although some of its material may go back to the time of the Rig Veda, and some parts of the Atharva-Veda are older than the Rig-Veda though not in linguistic form.
The Atharvana-Veda is preserved in two recensions, the Paippalāda and Śaunaka. According to Apte it had nine schools (shakhas). The Paippalada text, which exists in a Kashmir and an Orissa version, is longer than the Saunaka one; it is only partially printed in its two versions and remains largely untranslated.
Unlike the other three Vedas, the Atharvana-Veda has less connection with sacrifice. Its first part consists chiefly of spells and incantations, concerned with protection against demons and disaster, spells for the healing of diseases, for long life and for various desires or aims in life.
The second part of the text contains speculative and philosophical hymns. R. C. Zaehner notes that:
"The latest of the four Vedas, the Atharva-Veda, is, as we have seen, largely composed of magical texts and charms, but here and there we find cosmological hymns which anticipate the Upanishads, -- hymns to Skambha, the 'Support', who is seen as the first principle which is both the material and efficient cause of the universe, to Prāna, the 'Breath of Life', to Vāc, the 'Word', and so on.
In its third section, the Atharvaveda contains Mantras used in marriage and death rituals, as well as those for kingship, female rivals and the Vratya (in Brahmana style prose).
Gavin Flood discusses the relatively late acceptance of the Atharva-Veda as follows:
"There were originally only three priests associated with the first three Saṃhitās, for the Brahman as overseer of the rites does not appear in the Ṛg Veda and is only incorporated later, thereby showing the acceptance of the Atharva Veda, which had been somewhat distinct from the other Saṃhitās and identified with the lower social strata, as being of equal standing with the other texts."
The mystical notions surrounding the concept of the one "Veda" that would flower in Vedantic philosophy have their roots already in Brahmana literature, for example in the Shatapatha Brahmana. The Vedas are identified with Brahman, the universal principle (ŚBM 10.1.1.8, 10.2.4.6). Vāc "speech" is called the "mother of the Vedas" (ŚBM 18.104.22.168, 10.5.5.1). The knowledge of the Vedas is endless, compared to them, human knowledge is like mere handfuls of dirt (TB 22.214.171.124-5). The universe itself was originally encapsulated in the three Vedas (ŚBM 10.4.2.22 has Prajapati reflecting that "truly, all beings are in the triple Veda").
While contemporary traditions continued to maintain Vedic ritualism (Shrauta, Mimamsa), Vedanta renounced all ritualism and radically re-interpreted the notion of "Veda" in purely philosophical terms. The association of the three Vedas with the bhūr bhuvaḥ svaḥ mantra is found in the Aitareya Aranyaka: "Bhūḥ is the Rigveda, bhuvaḥ is the Yajurveda, svaḥ is the Samaveda" (1.3.2). The Upanishads reduce the "essence of the Vedas" further, to the syllable Aum (ॐ). Thus, the Katha Upanishad has:
- "The goal, which all Vedas declare, which all austerities aim at, and which humans desire when they live a life of continence, I will tell you briefly it is Aum" (1.2.15)
 In post-Vedic literature
Six technical subjects related to the Vedas are traditionally known as vedāṅga "limbs of the Veda". V. S. Apte defines this group of works as:
"N. of a certain class of works regarded as auxiliary to the Vedas and designed to aid in the correct pronunciation and interpretation of the text and the right employment of the Mantras in ceremonials."
The six subjects of Vedanga are:
- Phonetics (Śikṣā)
- Meter (Chandas)
- Grammar (Vyākaraṇa)
- Etymology (Nirukta)
- Astronomy (Jyotiṣa)
- Ritual (Kalpa)
 Supplementary Vedas
The term upaveda ("applied knowledge") is used in traditional literature to designate the subjects of certain technical works. Lists of what subjects are included in this class differ among sources. The Charanavyuha mentions four Upavedas:
- Medicine (Āyurveda), associated with the Rigveda
- Archery (Dhanurveda), associated with the Yajurveda
- Music and sacred dance (Gāndharvaveda), associated with the Samaveda
- Military science (Shastrashastra), associated with the Atharvaveda
But Sushruta and Bhavaprakasha mention Ayurveda as an upaveda of the Atharvaveda. Sthapatyaveda (architecture), Shilpa Shastras (arts and crafts) are mentioned as fourth upaveda according to later sources.
Some post-Vedic texts, including the Mahabharata, the Natyasastra and certain Puranas, refer to themselves as the "fifth Veda". The earliest reference to such a "fifth Veda" is found in the Chandogya Upanishad. "Dravida Veda" is a term for canonical Tamil Bhakti texts.
A traditional view given in the Vishnu Purana (likely dating to the Gupta period) attributes the current arrangement of four Vedas to the mythical sage Vedavyasa.. Puranic tradition also postulates a single original Veda that, in varying accounts, was divided into three or four parts. According to the Vishnu Purana (3.2.18, 3.3.4 etc) the original Veda was divided into four parts, and further fragmented into numerous shakhas, by Lord Vishnu in the form of Vyasa, in the Dvapara Yuga; the Vayu Purana (section 60) recounts a similar division by Vyasa, at the urging of Brahma. The Bhagavata Purana (12.6.37) traces the origin of the primeval Veda to the syllable aum, and says that it was divided into four at the start of Dvapara Yuga, because men had declined in age, virtue and understanding. In a differing account Bhagavata Purana (9.14.43) attributes the division of the primeval veda (aum) into three parts to the monarch Pururavas at the beginning of Treta Yuga. The Mahabharata (santiparva 13,088) also mentions the division of the Veda into three in Treta Yuga.