Divisions in each Veda                   
The contents of the Vedas are in the form of a collection of mantras. The word Mantra means ‘that which protects when repeated and reflected upon’. The Rig Veda mantras are called ‘Rik’ meaning hymns or stanzas of verses metrically set to convey definite meaning. The Sama Veda mantras are called ‘Saman’ meaning chants while Yajur Veda mantras are called ‘Yajus’ meaning sacrificial sentences.

These collections are called Samhitas. They bring out the purport of a Veda in the shape of mantras, methodically arranged. Samhita means that which is collected and arranged.

Each Veda is also divided into Samhita and Brahmana. The Brahmana includes within itself Aranyaka and Upanishad. Thus the division of the Vedas into these four categories suitable to the four stages of human life is as under:

a. Samhita
It is the name given to the collection of mantras or hymns and prayers in praise of Deities for attaining prosperity here and happiness hereafter. Samhita portion is considered as the principal text of a Veda. This portion is mainly meant for Brahmacharis, those who are in the first stage of their lives.

b. Brahmana
This portion of a Veda guides people in the performance of Vedic Karmas or sacrificial rituals; they are the prose explanations of the method of using the mantras in the Yajnas and other rituals. Brahmana is suitable for the householders, those belonging to the second stage in life.

c. Aranyaka
When one seeks the solitude of the forests (Aranya) for further concentration, the physical performance of Yajnas will be impracticable for various reasons more so due to old age. The Aranyaka portion is addressed to the people of that category offering a substitute for rituals. They teach methods of meditation based upon symbolical interpretations of sacrificial rites. It is a process of performing Yajnas and sacrifices at the mental level. For example Brihadaranyaka Upanishad starts with such analytical mental performance of Aswamedha Yajna. The Aranyakas are intended for the Vanaprasthas or people who prepare themselves for the last stage in life i.e. Sanyasa. Aranyakas form the transition link between the ritual of the Brahmanas and the philosophy of the Upanishads.

d. Upanishads
The Upanishads are the concluding portions of the Vedas which discuss philosophical issues. They are the essence of the Vedas containing their knowledge aspects. The philosophy of the Upanishads occupies the highest pedestal in the spiritual knowledge. They speak about the identity of the Supreme Eternal Soul, the Brahman, the individual soul, the Atman, their mutual relationship, the Universe (jagat) and man’s place in it. In short they deal with Jiva, Jagat and Jagadishwara.

As this is the core portion of the Vedas we shall be devoting more time on this topic later. Dr. Radhakrishnan puts it like this. “While the hymns or Samhitas are the creation of the poets, the Brahmanas are the work of the priests; the Upanishads are the meditations of the philosophers. The flow of thought from the Samhitas to Brahmanas to Aranyakas to Upanishads is the indication of the process of evolution of Hindu religion over the centuries”
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Thus we have in the Vedas portions dealing with the action or performance of rituals -. Karma Kanda, portions dealing with the method of worship and meditation - Upasana Kanda and lastly the portion dealing with the Highest knowledge, the knowledge of Brahman - Jnana Kanda. Roughly speaking, the Samhitas and Brahmanas constitute Karma Kanda, the Aranyakas the Upasana Kanda and the Upanishads the Jnana Kanda.

Sookta, Sootra and Shakha
Before going further we should be aware of what is meant by Sooktas, Sootras and Shakhas as we come across these terms frequently in the Vedic literature,

Sookta
The whole of the Rig Veda Samhita is in the form of verses. They are also called Rik or hymns in praise of different Devatas. In the later age these verses or Riks come to be called as Slokas or stanzas. Each Rik is a mantra and a number of Riks or mantras constitute a Sookta - examples are the popular Purusha Sooktam, Narayana Sooktam, Sri Sooktam etc.

Sootra
Sootras are aphorisms or declarations using minimum number of words to project a maximum dimension of thought. It is a short formula using the least possible number of letters giving no room for any ambiguity to express a sublime philosophic thought. Thus it contains the very essence of the thought and is absolutely faultless in its nature.

The best example is the famous Brahma Sootra which is also known as Vedanta Sootra or Sariraka Sootra which contains in a mystifying way the doctrines spelt out in the Upanishads. Because of their cryptic nature, Bhashyas or commentaries are necessary to understand Sootras. The names of other important Sootras are Patanjali Yoga Sootra, Narada Bhakti Sootra, Shandilya Bhakti Sootra, Ashtadhyayi of Panini etc. In fact the six Vedangas mentioned above and the six systems of Hindu philosophy - Shad Darshanas form the most important twelve sets of Sootra literature of Hinduism.

Shakha - its plan and purpose
The Samhitas in course of time branched off leading to the formation of Shakhas or recensions. The branching off of the Vedic traditions took place as a result of several factors such as geographical location of the priests, ritual specialization and doctrinal disputes.

Each of the principal sages had several disciples. These disciples or their successors might have done some editing of the Vedic mantras to suit the rites they were required to perform and the geographical locations where they were placed over which the local culture also must have had its influence. Another reason given for the division of Vedas into many Shakhas is the vastness of the subject to be covered by a student for achieving his spiritual goal.

The scheme of Vedic learning is first studying and recitation of the hymns (Samhita) followed by performance of Yajnas (Brahmana), then an enquiry into the rationale behind the performance of these Yajnas (Aranyaka) and lastly, an enquiry into ‘Paramatma Tattwa’ and attaining its actual experience (Upanishad). Since mastering these tasks in their entirety is an almost impossible job, a method in the form of Shakhas of the Vedas was evolved whereby only the optimum required for each purpose was taught. Each Shakha thus contains that many mantras under each category of Samhita, Brahmona, Aranyaka and Upanishad as would enable a seeker to accomplish liberation or Moksha,