They are India's proudest and most ancient possessions.It hardly matters if you are a Christian or a Muslim or even a Pakistani-as long as you have Indian DNA. They are an amazing collection of writings from original oral transmissions, which have been aptly described by Shri Aurobindo as "the supreme work of the Indian mind".It is here that we find all the fundamental teachings that are central to Hinduism — the concepts of 'karma' (action), 'samsara' (reincarnation), 'moksha' (nirvana), the 'atman' (soul), and the ' Brahman' (Absolute Almighty).For example, the Upanishads describe rites or performances designed to grant power or to obtain a particular kind of son or daughter.One Upanishadic concept had tremendous impact on subsequent Indian thought.
Of the four Vedas, Rigveda, Samaveda and Yajurveda are considered the original triad (Triveda).
Western scholars have called them the first “philosophical treatises” of India, though they neither contain any systematic philosophical reflections nor present a unified doctrine.
Indeed, the material they contain would not be considered philosophical in the modern, academic sense.
It points to a period in time when groups of pupils sat near the teacher and learned from him the secret teachings in the quietude of forest 'ashrams' or hermitages.
In another sense of the term, ' Upanishad' means ' Brahma-knowledge' by which ignorance is annihilated.