The five sheaths (pancha-kosas) are described in the Taittiriya Upanishad. 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, and they are often visualised as the layers of an onion.
From gross to fine they are:
"foodstuff" sheath (Anna)
"energy" sheath (Prana/apana)
Manomaya kosha "mind-stuff" sheath (Manas)