Panchakoshas (Devanagari: पंचकोश, the five sheaths), are the layers of body that seemingly cover the Atman (Self or Consciousness). The Tvam ("Thou") padartha of the Mahavakya Tat Tvam Asi is determined by the analysis of Panchakoshas that are not the atman. Panchakoshas are discussed in the Brahmanandavalli Chapter of Taittiriya Upanishad which is a part of the Taittiriya Samhita of the Krishna Yajur Veda and in which particular chapter is discussed ways and means to achieve Brahman. It gives a detailed description of the dimensions of human personality or the dimensions of the Self.