A shakha (Sanskrit kh?, "branch" or "limb"), is a Hindu theological school that specializes in learning certain Vedic texts, or else the traditional texts followed by such a school. An individual follower of a particular school or recension is called a khin. The term is also used in Hindu philosophy to refer to an adherent of a particular orthodox system.
A related term cara?a, ("conduct of life" or "behavior") is also used to refer to such a Vedic school: "although the words cara?a and kh? are sometimes used synonymously, yet cara?a properly applies to the sect or collection of persons united in one school, and kh? to the traditional text followed, as in the phrase kh?m adhite, ("he recites a particular version of the Veda")". The schools have different points of view, described as "difference of (Vedic) school" (kh?bheda?). Each school would learn a specific Vedic Sa?hita (one of the "four Vedas" properly so-called), as well as its associated Brahmana, Aranyakas, Shrautasutras, Grhyasutras and Upanishads.
In traditional Hindu society affiliation with a specific school is an important aspect of class identity. By the end of the Rig Vedic period the term Br?hma?a had come to be applied to all members of the priestly class, but there were subdivisions within this order based both on caste and on the shakha (branch) with which they were affiliated. A Br?hma?a who changed school would be called "a traitor to his kh?" (kh?raa?).
The traditional source of information on the shakhas of each Veda is the Cara?a-vy?ha, of which two, mostly similar, versions exist: the 49th pari?ia of the Atharvaveda, ascribed to Shaunaka, and the 5th pari?ia of the ?ukla (White) Yajurveda, ascribed to K?ty?yana. These have lists of the numbers of recensions that were believed to have once existed as well as those still extant at the time the works were compiled. Only a small number of recensions have survived.
The schools are enumerated below, categorised according to the Veda each expounds.
?aunaka's Cara?a-vyuha lists five shakhas for the Rig Veda, the kala, Bkala, A?val?yana, ?a?kh?yana, and Muk?yana of which only the kala and Bkala and very few of Asvalayana are now extant. The Bashkala recension of the Rigveda has the Khilani which are not present in the Shakala text but is preserved in one Kashmir manuscript (now at Pune). The Shakala has the Aitareya-Brahmana, The Bashkala has the Kausitaki-Brahmana.
Shri Gurucharitra mentions 12 shakhas for the Rig Veda namely ?r?vak?, ?rava?iy?, ja, ?apha?a, phakrama(2), daa, a?val?yan?, kh?yan?, kal?, bkal? and m?k? (?, , , , ?(2), ?, , , , ?, ) in Ovi 35 to 38.
There is, however, Sutra literature from the A?val?yana shakha, both a shrauta sutra and a grhya sutra, both surviving with a commentary (vrtti) by Gargya Naranaya. Gargya Naranaya's commentary was based on the longer commentary or bhashya by Devasvamin, written in the 11th century.
The ?a?kh?yana shakha has been recently rediscovered in Banswada in Rajasthan where two septuagenarians are the last surviving practitioners. 
?aunaka's Cara?a-vyuha lists forty-two or forty-four out of eighty-six shakhas for the Yajur Veda, but that only five of these are now extant, with a sixth partially extant. For the Yajur Veda the five (partially in six) shakhas are the (Vajasaneyi Madhandina, Kanva; Taittiriya, Maitrayani, Caraka-Katha, Kapisthala-Katha).
The Yajurvedin shakhas are divided in Shukla (White) and Krishna (Black) schools. The White recensions have separate Brahmanas, while the Black ones have their(much earlier) Brahmanas interspersed between the Mantras.
|Madhyandina (VSM)||Currently recited by all over North Indian Brahmins and by Deshastha Brahmins||Madhyandina Shatapatha (SBM)||survives as Shatapatha XIV.1-8, with accents.||Brihadaranyaka Upanishad = SBM XIV. 3-8, with accents, Ishavasya Upanishad = VSM 40|
|Kanva (VSK)||Currently recited by Utkala Brahmins, Kannada Brahmins, Karhade Brahmins and few Iyers||Kanva Shatapatha (SBK)(different from madhyandina)||survives as book XVII of SBK||Brihadaranyaka Upanishad=SBK,with accents, Ishavasya Upanishad = VSK 40|
|Taittiriya||TS,Present all over South India and in Konkan||Taittiriya Brahmana (TB) and Vadhula Br. (part of Vadhula Srautrasutra)||Taittiriya Aranyaka (TA)||Taittiriya Upanishad (TU)|
|Maitrayani||MS,Recited by few Brahmins in Nasik||-||virtually same as the Upanishad||Maitrayaniya Upanishad|
|Caraka-Katha||Katha Aranyaka (almost the entire text from a solitary manuscript)||Kathaka Upanishad, Katha-Shiksha Upanishad|
|Kapishthala||KapS (fragmentary manuscript, only first sections accented), edited (without accents) by Raghu Vira.||-||-|
?aunaka's Cara?a-vyuha lists twelve shakhas for the Sama Veda out of a thousand that are said to have once existed, but that of these only one or perhaps two are still extant. The two Samaveda recensions are the Jaiminiya and Kauthuma.
In Ovi 203 to 210 of chapter 27, Shri Gurucharitra mentions 8 of the thousands of shakhas namely ?sur?yay?, v?sur?yaya, v?t?ntarey?, prjal?, ?jñagvainavidh?, pr?c?na yogyakh?, jñ?nayoga and ryay? (?, , , , ?, ? , , ). Of these ryay? () has 10 shakhas namely ryay?, skhy?yan?, hy?, mugdala, khalval?, mah?khalval?, lgal?, kaithum?, gautam? and jaimin? (, ?, , , , , , , , ).
|Kauthuma||edited,Recited by all over North and in South India||edited (8 Brahmanas in all), no accents||None. The Samhita itself has the 'Aranyaka'.||Chandogya Upanishad|
|Ranayaniya||Manuscripts of Samhita exist.Recited by Gokarna,and Deshastha Brahmins||Same as Kauthuma with minor differences.||None. The Samhita itself has the 'Aranyaka'.||Same as Kauthuma.|
|Jaiminiya/Talavakara||Samhita edited.Recited by Nambudiris and choliyal of Tamil nadu Two distinct styles of Saman recitation, partially recorded and published.||Brahmana published (without accents) - Jaiminiya Brahmana, Arsheya Brahmana||Tamil Nadu version of Talavakara Aranyaka (=Jaiminiya Upanishad Brahmana) published||Kena Upanishad|
Only one shakha of an original nine is now extant for the Atharvaveda. The nine sakhas were Paippalada, Tauda, Mauda, Shaunakiya, Jajala, Jalada, Brahmavada, Devadarsa and Chaarana-Vaidya. In Ovi 217 to 219 of chapter 27, Shri Gurucharitra mentions 9 shakhas namely paippal?, d?nt?, pradta, stot?, aut?, brahmad? ya?ad?, ?aunak?, vedadar and cara?avidy? (?, , ?, , , ?, , , )
The Shaunaka is the only shakha of the Atharvaveda for which both printed texts and an active oral tradition are known to still exist.
For the Atharvaveda, both the Shaunakiya and the Paippalada traditions contain textual corruptions, and the original text of the Atharvaveda may only be approximated from comparison between the two.
|Shaunaka||AVS, edited and recited by all over North India and South India||Fragmentary Gopatha Brahmana (extant and published), no accents.||-||Mundaka Upanishad (?) published.|
|Paippalada||AVP; recited by Utkala Brahmins as samhita patha only. otherwise, two manuscripts survive: Kashmiri (mostly edited) and Oriya (partly edited, by Dipak Bhattacharya and others, unaccented)||lost,similar to that of Gopatha Brahmana||-||Prashna Upanishad, Sharabha Upanishad etc. - all edited.|
The Paippalada tradition was discontinued, and its text is known only from manuscripts collected since the 20th century. However some Orissa Brahmins  still continue the tradition of Paippalada. No Brahmana is known for the Shaunaka shakha. The Paippalada is possibly associated with the Gopatha Brahmana.