The word Vedanta means 'the end of the Vedas'. Primarily, the word understood for the Upanishads, though afterwards its denotation widened to include all thoughts developed out of the Upanishads, The Upanishads may be regarded as the end of the Vedas in different senses, firstly, the Upanishads were the last literary products of the Vedic period. Three kinds of literature of this period can be broadly classified: the earliest being the Vedic mantras, the next being the Brahmanas, which guide and encourage the Vedic rituals and the last, the Upanishads, which discuss the philosophical tattvas or matters comprehensively. In a broad sense, these were called the Srutis or Vedas. Secondly, in respect of study also, the Upanishads come last. As a rule, a man should study the Vedic Samhitas first, with the help of Brahmanas and Vedangas. But finally, he should read the Upanishads, as these texts help him to understand the real meaning of life and life after death. These spiritual texts teach man the mystery of life as well as the universe in the right way. Thirdly, the Upanishads may be regarded as the end of the Veda, also in the sense that they mark the culmination of the Vedic speculation. Generally, the word Upanishads means, what destroys ignorance and gets man near or closer to God,' or 'what gets the man near to the teacher'. However, the Upanishads were regarded as the inner or secret meanings of the Vedas; hence, their teachings were sometimes called Vedopanisad or the mystery of the Vedas (Taittiriya Upanishads, I.11).
Hence, Vedanta or Uttara-Mimamsa is the standard and the characteristic Philosophy of India. It is based on the oldest spiritual intuitions of the Upanishads, developed, systemized and updated by an unbroken tradition of great sages and Acharyas. Though the name of Vedanta does not occur in the old Upanishads, we can hardly doubt that it was the Vedantic thoughts, contained in the Upanishads, which gave the first impulse to more systematic philosophical speculations in India. Several scholars have tried to prove that Samkhya's ideas prevailed in India at an earlier time than the Vedantatic ideas. But though there certainly are germs of Samkhya theory in the Upanishads, they are but few and far between while the strictly Vedantic concepts meet us at every step in the hymns, the Brahmanas, the Aranyakas and in the Sutras. Vedanta is the native philosophy of India. Indeed, this philosophy is not yet treated systematically in the Upanishads, but neither is the Samkhya. To us, who care only for the growth of philosophical thought on the ancient soil of India, Vedanta is the first growth; and the question is whether Kapila lived before Badarayana, or whether the systematic treatment of the Samkhya took place before that of Vedanta can hardly arise.
However, there is no doubt that the Upanishads are the abstract of all Vedas & it contains the mystery of all sacred knowledge, which may help a man to get liberation. The Upanishads were many and developed in the different Vedic Schools at different times and places. The problems discussed, and solutions offered presented differences, despite the unity of the general outlook. The need was felt, therefore, of course, time for systemizing the different teachings to bring out the harmony underlying them. Badarayana's Brahma-Sutras or Sariraka-Sutras or Vedanta-Sutras or Uttar Mimamsa undertakes this task.
The Brahma Sutras attempt to reconcile the seemingly contradictory and diverse statements of the various Upanishads and the Bhagavad Gita, by placing each teaching in a doctrinal context. The word "sutra" means "thread", and the Brahma Sutras stitch together the various Vedanta teachings into a logical and self-consistent whole. However, the Brahma Sutras are so terse that not only are they capable of being interpreted in multiple ways, but they are often incomprehensible without the aid of the various commentaries handed down in the main schools of Vedanta thought. The Vedanta-Sutras supply ample evidence that at a very early time, i.e. a period before their final composition, there were differences of opinion among the various interpreters of the Vedanta. These sutras systematic the Jnana-Kanda (path of wisdom, as opposed to Karma-Kanda, the path of action) of the Veda, by combining the two tasks of concisely stating the teaching of the Veda and argumentatively establishing the specific interpretation of the Veda adopted in the sutras. The sutras also discuss the role of karma and God and critically address the various doctrines associated with Buddhism, Jainism, Yoga, Nyaya Vaisesika, Saiva, Sakta, Atheism and Samkhya Philosophies.
In the canon of Vedanta literature, the Brahma Sutra occupies a unique position as the oldest systematic commentary on the Upanishads. It defines the thread of Life Force (prana) by which all of the universal objects are bound together. The Brahma Sutras also constitute the Nyaya-prasthana, the logical starting point of the Vedanta philosophy (Nyaya = logic/order). No study of Vedanta is considered complete without a close examination of the Prasthana tray, the texts that stand as the three starting points. While the Upanishads (Sruti-prasthana, the starting point of revelation) and the Bhagavad- Gita (Smrti-prasthana) are the starting point of remembered tradition (are the basic source texts of Vedanta, it is in the Brahma Sutras that the teachings of Vedanta are outlined in a systematic and logical order.
The Brahma Sutras consist of four Chapters (Adhyayas). Each Chapter (Adhyaya) is divided into four padas (parts) and each pada consists of single or several groups of Sutras called Adhikaranas. A total of 191 Adhikaranas is containing 555 Sutras, (aphorisms) in the Brahma –Sutras
The First Chapter explains that all the Vedanta texts talk of Brahman, the Ultimate Reality, which is the goal of life. There are thirty-nine Adhikaranas and one hundred thirty-four Sutras in this Chapter. The first, pada contains eleven Adhikaranas with thirty-one Sutras, the second pada contains seven Adhikaranas with thirty-two Sutras, the third pada contains thirteen Adhikaranas with forty-three Sutras, and the fourth pada contains eight Adhikaranas with twenty-eight Sutras.
The Second Chapter discusses and refutes the possible objections to Vedanta philosophy. There are forty-seven Adhikaranas and one hundred fifty-seven Sutras in this Adhyaya. The first, pada contains thirteen Adhikaranas with thirty-seven Sutras, the second pada contains eight Adhikaranas with forty-five Sutras, the third pada contains seventeen Adhikaranas with fifty-three Sutras, and the fourth pada contains nine Adhikaranas with twenty-two Sutras.
The Third Chapter describes the process by which Ultimate Emancipation can be achieved. There are sixty-seven Adhikaranas and one hundred eight-six Sutras in this Chapter. The first, pada contains six Adhikaranas with twenty-seven Sutras, the second pada contains eight Adhikaranas with forty-one Sutras, the third pada contains thirty-six Adhikaranas with sixty-six Sutras, and the fourth pada contains seventeen Adhikaranas with fifty-two Sutras.
The Fourth Chapter elaborates on the state that is achieved in Final Emancipation. There are thirty-eight Adhikaranas and Seventy-eight Sutras in this Chapter. The first pada contains fourteen Adhikaranas with nineteen Sutras. The second pada contains eleven Adhikaranas with twenty-one Sutras. The Third pada contains. Six Adhikaranas with sixteen Sutras, The fourth pada contains seven Adhikaranas with twenty-two Sutras.
However, in short, it can be said that the First Chapter exclusively elaborates that all the Vedanta texts talk of Brahman, the Ultimate Reality, which is the goal of life. The very first Sutra offers an indication into the nature of the subject matter of Brahma Sutra (I.1.1 that Brahma jijnasa- Now: therefore the inquiry (into the Real Nature) of Brahman. The whole Brahma Sutra very clearly explains in detail the True Nature and Form of Brahman. The second Chapter discusses and refutes the possible objections to Vedanta Philosophy. The third Chapter specifies the process by which Ultimate Emancipation (moksa) can be achieved. The fourth Chapter talks about the state that is achieved in Final Liberation or moksha.