The Vedangas are the last treatises of the Vedic Literature. Paniniya Shiksha (41-42) narrates two verses on the importance of the Vedangas which describe Veda as a Purusha having six limbs as six Vedangas: Chandas are His two feet, Kalpa are His two arms, Jyotisha are His eyes, Nirukta is His ears, Shiksha is His nose and Vyakarana is His mouth.The oldest record of their names occurs in the Mundaka Upanishad (1.1.5) where they are named as:

1. Shiksha or phonetics or pronunciation
2. Kalpa or ritual
3. Vyakarana or grammar
4. Nirukta or etymology
5. Chandas or meter
6. Jyotisha or astronomy

Now we shall briefly study about them in the order, given in the Mundaka Upanishad.

Shiksha really means instruction: then in particular ‘instruction in reciting’ i.e., in correct pronunciation, accentuation etc. of the Samhita texts. Later, it was a name given to works containing rules regarding the proper pronunciation of Vedic texts. Thus, the Shiksha-Sutras are treatises on phonetics. They are related to the Samhita and, therefore, are almost as old as the Kalpa-Sutras.
Shiksha lays down the rules of phonetics – sounds of syllables, of pronunciation. The function of the Shiksha is thus to fix the parameters of Vedic words. Phonetics is most important in the case of the Vedic language, because we see that change in sound leads to change in results and effect. Hence, Shiksha which is Vedic Phonetics has been regarded as the most important of the six Angas (organs) of the Veda Purusha.Some important Pratishakhyas are:
(1) Rigveda-Pratishakhya of Rigved
(2)Taittiriya-Pratishakhya of Krishna Yajurveda
(3) Vajasaneyi Pratishakhya of Shukla Yajurveda
(4) Atharvaveda-Pratishakhya of Atharvaveda

The second Vedanga is Kalpa (ritual) which is called the arms of the Veda Purusha. It is especially intended for the proper application of the Vedic texts. The oldest Kalpasutras are those which in their contents are directly connected with the Brahmanas and Aranyakas. It was the ritual (Kalpa), the chief contents of the Brahmanas, which first received systematic treatment in the manuals called the Kalpasutras. They contain the rules in the Sutra style, referring to sacrifices, with the omission of all things which are not immediately connected with the ceremonial. They are more practical than the Brahmanas which for the most part are taken up with mystical, historical, mythological, etymological and theological discussions. They are also considered significant for the study of Vedic culture and society.

There are four types of the Kalpasutras:
(1) Shrauta-sutras,dealing with Shrauta sacrifices
(2) Grihya-sutras, dealing with the domestic ceremonies
(3) Dharma-sutras, dealing with the religious and social laws
(4) Shulba-sutras, dealing with the rules of measurement of the fire-altars etc.

The third Vedanga is Vyakarana or grammar, which is necessary for the understanding of the Veda. It is called the mouth of the Veda Purusha. The old Vedanga-texts on Vyakarana are entirely lost today. In the Aranyakas, we find some technical terms of grammar. The only representative of this Vedanga is the Ashtadhyayi of Panini, which belongs to a later period. It is indeed the most celebrated text-book of grammar. It is not associated with any Vedic school. Due to its great merits, this may be assumed that Panini superseded all his predecessors, whose works have consequently perished.

Formation of the word is the main subject of grammar. It discusses root (Prakriti) and suffix (Pratyaya) of a word to study its meaning. Panini’s Vyakarana is in the form of sutras or aphorisms. The fourteen Sutras are referred to here, as Maheswara Sutras. They were originated from Nataraja’s damuru sound. They are considered the foundation of grammar. Vararuci has written an elaborate commentary or Vartika. Sage Patanjali wrote commentary or Bhashya on it.

Nirukta Vedanga is called the ears of the Veda Purusha. ‘Nirukta’ means ‘etymology’ and it explains the reason why a particular word has been used i.e., the meaning of usage. The only work which has survived as a specimen of this Vedanga ‘etymology’ is the Nirukta of Yaska. It is a commentary on Nighantu which is ‘list of words’ found in the Vedas. Tradition ascribes the Nighantu also to Yaska. The Nighantus are five lists of words, which are again divided into three sections. The first section consists of three lists, in which Vedic words are collected under certain main ideas. The second section contains a list of ambiguous and particularly difficult words of the Veda, while the third section gives a classification of the deities according to the three regions, earth, sky and heaven. Yaska explained these lists in the twelve books followed. The most interesting portion of the Nirukta is the discussion which covers the whole of the first book and a part of the second, as well as the seventh book, which was as an admirable introduction to the study of the Veda.

Yaska has mentioned a considerable number of important grammarians as his predecessors in the Nirukta such as Galava, Shakapuni, Katthakya.

Niruka is very important for several reasons. Firstly, it represents the type of the earliest classical style and in this respect stands by itself. Secondly, it is the oldest known attempt in the field of Vedic etymology. As regards the importance of the etymology Yaska himself says that without it the precise meanings of the Vedic stanzas cannot be understood

Chandas Vedanga is regarded as the feet of the Veda Purusha. The body of the Vedas rests on the Chandas which are in the nature of feet. Each Mantra of the Veda has a special Chandas, just as it has a presiding Devata.

According to Nirukta the term Chandas is derived from the root Chad (to cover). Meter is called Chandas because it covers the sense of the Mantra. The Chandas is designed for the purpose of securing the proper reading and reciting of Vedic texts. The literature comprising this Vedanga on metrics is equally small.

The texts, dealing with Vedic meters, are as follows:
1. Rikpratishakhya 2. Shankhayana Shrauta-sutra 3. Nidana-sutra of Samaveda
4. Chandas-sutras of Pingala

Each of them contains a section varying slightly from each other on Vedic meters.

The last Vedanga Jyotisha is called eye – the organ of sight, of the Veda Purusha. The object of Jyotisha Vedanga is not to teach astronomy, but to convey such knowledge of the heavenly bodies as is necessary for fixing the days and hours of the Vedic sacrifices. It gives some rules for calculating and fixing time for sacrifices. In the Brahmanas and Aranyakas, we find frequent allusions to astronomical subjects, and even in the hymns we find traces which indicate a certain advance in the observation of the moon.

It is unfortunate that there is no work available at present dealing with ancient Vedic astronomy (Jyotisha) in the Sutra style. Only we have a small text-book called Jyotisha of Vedic astronomy in verses in two recessions. Generally, Maharshi Lagadha is regarded author of this Vedanga Jyotisha. This is a very difficult text and, therefore, is not clear on several points to scholars even today. Later, we find many Sanskrit treatises on astronomy and mathematical calculations. Bhaskaracharya, Varahamihira and Aryabhatta are known ancient scholars conversant with these scientific subjects. The principles established by them are in use in the modern world. By Dr.Shashi Tiwari (Retd.), Sanskrit Department, Delhi university