Upnishads for the basis of Hindu philosophy. They contains the teachings that describe Hindu religion- it’s concept of Karma, truth and Moksha, Soul and the universe.The word Upanishad means to sit closely and listen. Hence they take us a step ahead or closer to hindu religion. While the actual meaning is “knowledge of Brahma”.Upanishads are believed to be older than Vedas. It is believed that they were written around 400-800 BC.It is believed that more than 200 Upanishads exist in Hindu religion however only 13 are known to human knowledge namely Chandogya, Kena, Aitareya, Kaushitaki, Katha, Mundaka, Taittriyaka, Brihadaranyaka, Svetasvatara, Isa, Prasna, Mandukya and the Maitri Upanishads.
The true preachings of Upanishads can be adopted in one’s life by knowing one’s soul or aatma. There were many authors of Upanishads but two that are known to human knowledge are Yajnavalkya and Uddalaka Aruni. Shvetaketu and Shandilya are some other important names on the list.