Kosha

A kosha (also kosa; Sanskrit कोश, IAST: kośa), usually rendered "sheath", is a covering of the Atman, or Self according to Vedantic philosophy. There are five koshas (Panchakoshas; Devanagari: पंचकोश; the five sheaths), and they are often visualised as the layers of an onion in the subtle body. 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.