The common dictionary meaning of the word ‘Sutra’ in Sanskrit is thread, string or cord. The word ‘Sutra’ as used in literary context has a wider meaning. One of the ancient texts called “Padma Purana” offers the following definition of the word ‘Sutra’ in a literary context:
“That which is of few words, unequivocal, expresses a vast idea in a gist form, is non-repetitive and doesn’t contain any fault is known as a Sutra.”
In other words, a Sutra is an aphoristic or cryptic statement which expresses a vast idea within a few words. Some scholars say that extremely important works were written in Sutra form so that they could be easily memorized and retained for the benefit of posterity. A Sutra is like a quick note jotted down by a speaker, on which he would elaborate when delivering a lecture.
According to the ancient authors, a Sutra should have six characteristics:
“Clear conception, technical language, laying down the process, rules, analogy and authority are the six characteristics of a Sutra.”
Many an important work in ancient times were written in Sutra form. “Brahma Sutras” by Vyasa, which expound the Vedanta philosophy, “Yoga Sutras” by Patanjali which deal with Yoga philosophy, “Bhakti Sutras” by Narada, which explain Bhakti Yoga, “Nyaya Sutras” by Gautama which delve into the Nyaya philosophy are examples of some great works written in Sutra form.
>Sutras, being very brief, are not easy to unravel. A work in Sutra form is usually elaborated by what is called a “Bhashyam” or commentary. Bhashyam is defined as:
"That which elaborates the meaning of the Sutra in words synonymous to those of the Sutra as well as in its own words is a Bhashya."
The following are the characteristics of a Bhashya or Commentary:
>"Division of the words, explaining the meaning of words, derivation of words, meaning of the sentences and answering the objections are the five characteristics of Bhashya."