This Upanishad has derived its name from the six prasnas or questions. It belongs to the Atharvaveda. There are six chapters in the Upanishad, and each begins with a question. The first question refers to the origin of the created things the second to the constituents of the human personality the third to the nature and origin of Prana the fourth is about the psychological aspect of the human personality the fifth about Pranava and the sixth about the metaphysical principle in man. Moreover in this Upanishad alone we find a clear mention being made of the creation originating from Matter and Energy.