Structure of the Vedas                 
We will now enter into the inner sanctum sanctorum of the Vedas and look at the treasures contained therein.

It is to be born in mind here that conventionally speaking, it is the Samhita that is indicated when we use the word Veda. Rig Veda means Rig Veda Samhita. So also is the case with the other Vedas. The Brahmanas, Aranyakas and Upanishads have independent names.

Rig Veda Samhita
Of all the four Vedic Samhitas, the Rg. Veda Samhita is the oldest and occupies a pride of place in the Vedic literature. The whole of Rig Veda Samhita is in the form of verse. It is a collection of Sooktas or hymns revealed to various Rishis at different periods of time. Hence a variety of ideas, styles of language, grammar, historical and cultural factors are found here. This Samhita contains masterpieces of poetic compositions like the famous Purusha Sooktam and the morning prayers to Ushas, the goddess of dawn. It was said to have 21 Shakhas but now only five of them are known to exist.

According to the ancient tradition, the whole Rig Samhita has been divided into 10 Mandalas. The Mandalas are subdivided into Anuvakas, the Anuvakas into Sooktas and Sooktas into mantras as follows.

Rig Veda contains 10552 mantras spread over 1028 Sooktas and 85 Anuvakas in 10 Mandalas. The topics dealt with in the Rig Veda Samhita can be classified into 3 groups.

The first group is in praise of the deities like Agni, lndra, Varuna, Mitra and others. The Vedic deities numbering 33 are assigned to the three regions of the universe  viz. earth (Prithvi), heaven (Dyaus) and intermediary space (Antariksha). Although these deities appear as personifications of forces of nature, they are actually different facets of Brahman, the Only One Supreme Reality. The famous mantra on this point ‘ekam sat viprah bahudha vadanti’ meaning ‘Truth is one, sage’s call it by various names’ occurs in this Samhita.

The second group is concerned with philosophical speculations like the origin of the Universe and the real nature of human beings. Although the Samhita is a book of laudatory hymns still all the later ideas of Vedanta including Jnana and Bhakti are found therein at least in a rudimentary form. However, advocacy of worship of God with form and qualities - Sagunoposona - is predominant.

The proclamation contained in various mantras show that it teaches eka-devata-vada or monotheism and not polytheism. For example, the Samhita states that God creates the world out of Himself and rules over it; He is omnipresent (present everywhere), omnipotent (all powerful) and omniscient (all knowing), He is ever perfect, infinitely compassionate, easily approachable by the devotees and He grants us immortality. But the idea about actual process of creation of the universe finds a place only in the later Vedantic  literature i.e. the Upanishads.

The third group deals with several secular subjects like marriage, war etc., which show the nature of society of those times. A just and equitable social order existed. However, social life was conditioned by spiritual consciousness. There was Samanvaya or harmony of life here and hereafter. Satya (truth) and Dharma (righteousness) are glorified and Amritatva (immortality) as the goal of life was accepted.

The Brahmanas, Aranyakas and the Upanishads of this Veda are
1. Aitareya and Kausitaki Brahmanas
2. Aitareya and Sankhyayana Aranyakas and
3. Aitareya and Kausitaki Upanishads

Yajur Veda Samhita
It is a collection of Yajus or the mantras in prose which give procedural details to the Adhvaryu priest for the proper performance of Yajnas. The popular hymn in praise of Lord Siva - Sri Rudraprasna – finds a place in this Veda. The other famous prayer Purusha Sooktam also occurs here with some modifications.

Yajur Veda Samhita is in two parts viz. Krishna Yajurveda and Shukia Yaiurveda. Krishna Yajurveda was taught by sage Vaishampayana. It is considered older than the Shukla Yajurveda. Today a vast majority follow the Yajur Veda. Krishna Yajurveda is common in the South and Shukla Yajurveda in the North.

Krishna Yajurveda Samhita is said to have contained 85 Shakhas but only four of them are available now out of which the Taittiriya Samhita is widely prevalent especially in South Jndia. It deals with detailed descriptions of sacrifices like Rajasuya, Vajapeya, Somayaga etc. The other three Shakhas are not so well known though they also deal with similar sacrifices.

Related to this Samhita are-
1. Taittiriya Brahmana
2. Taittiriya and Maitrayani Aranyakas
3. Taittiriya, Katha, Swetaswatara, Maitrayani and Moha Narayana Upanishads.

Shukla Yajurveda Samhita is said to have been brought to the knowledge of the World by the famous sage Yajnavalkya from Vaajasani which means the Sun God. Hence this is also known as Vajasneyi Samhita, This is entirely in verse form.

Out of 17 Shakhas of this Samhita said to hove been existed; only two viz. Kanva and Madhyandina Shakhas are presently existing. The former is common in South India while the latter is popular in the North. This Samhita also deals mainly with Yajnas like Agnishtoma.

Related to this Samhita are-
1. Satapatha Brahmana. This is a work extensively serving as a general guide to all the        Vedas.
2. Brhad-Aranyaka and
3. Brhadaraanyokoponishad and Isavasyopanishad.

Samaveda Samhita
Samaveda Samhita is the highly commended scripture of Hinduism. However it is not considered as an independent work. All the mantras of the Rig Veda which are useful to Udgatir priest for chanting in the Yajnas to ensure the grace of the Gods have been brought together in this Veda. ‘SA’ means a mantra of the Rig Veda, ‘AMA’ means musical notes. Hence a Saman is a mantra of the Rig Veda set to music. The word Saama also means that which brings peace to the mind. Although this Veda is said to have 1000 Shakhas only three are available now.

Unlike the mantras of the other three Vedas, the mantras of Samaveda are simply known as Saman having seven svaras or musical scales. Therefore, Saama Gana or singing of hymns as per the rules of Sama Veda is said to be the basis and source of the seven svaras or notes fundamental to the Indian music systems.

The special virtue of Sama Veda is that although its mantras are from the Rig Veda they are set to music which is greatly conductive to the spiritual evolution of a human being and to qualify oneself for receiving the grace of the Gods. Hence, Sri Krishna says in the Gita (Ch.10 Verse 22) ‘vedaanaam saamavedosmi’ meaning ‘among the Vedas I am the Sama Veda’. Similarly, in the Lalita Sahasranama, one of the epithets used to describe the Divine Mother is ‘Saama Gaana Priye’ meaning one who is pleased with the recital of Saman.

Affiliated to this Samhita are-
1. Out of 9 Brahmanas of this Veda Tandya Maha Brahmana is the biggest and most important.
2. Only one Aranyaka of this Samhita is available which is called Talavakara or Jaiminiya Aranyaka.
3. The well known Chandogya Upanishad and the Kenopanishad, which is also known as Talavakaropanishad, are from this Veda.

Atharva Veda Samhita
Atharva means purohit or pundit. This Veda is said to have been brought to light by a Sage called Atharvan and hence this name. This is also called Brahma Veda because it is assigned to the Brahma priest who supervises the conduct of the Yajnas. The mantras in this Veda are both in prose and verse forms,

As the Atharva Veda Samhita has some special features it stands apart from the other three Vedas. It deals more with things here and now than with the hereafter and the sacrifices are utilized as a means to them.

This Veda contains many types of mantras designed to ward off evils and hardship as also to destroy enemies. Besides this it deals with diseases and their cure, rites for prolonging life, for fulfilling one’s desires, construction activities, trade and commerce, statecraft, defense systems of the country etc.

Many hymns deal with creation and emergence of the Universe. The hymn extolling the wonder of creation is called Prithvi Sooktam. Amidst these mundane subjects high philosophical ideas are also found in this Veda. The literary style of this Veda is highly sophisticated.

Most of the Shakhas of Atharva Veda are lost. Out of the 9 Shakhas known to have existed under this Samhita only two are available now. They are Pippalada and Saunaka. Only one Brahmana called Gopatha Brahmana has been discovered. No Aranyaka of this Veda has come to light so far.

There are a number of Upanishads which are associated with this Veda. The three well known Upanishads viz. Prasna, Mundaka and Mandukya as also the Kaivalya Upanishad belong to this Veda.