The Mandukya Upanisad is the shortest amongst the principal Upanisad-s having just 12 manta-s but presents the quintessence of our entire Upanisadik teaching. It analyses the entire range of human consciousness in the three states of waking (jagrat), dream svapna) and dreamless sleep (susupti) which are common to all men. It asserts unequivocally that the Absolute Reality is non-dual (advaita) and attributeless (nirguna). It has a unique method of approach to truth. It provides symbol for meditation in the mono-syllable AUM-comprising of three sounds A, U, M, detailing its philosophical implications. According to Muktikopanisad, it forms the epitome of all the hundred and eight Upanisad-s which have been accepted as authentic.