KOSHA is a Sanskrit term meaning "sheath" or "vehicle of awareness". In Indian philosophy it is used to differentiate the "five sheaths" that envelop the pure awareness of being or the genuine Self, as opposed to the ego.
The coarse body is the physical organism. It contains only the food-apparent-sheath "annamaya-kosha" nourished by food.
The fine body contains three sheaths: the vital energy sheath "prânamaya-kosha", the mental-emotional sheath "manomaya-kosha" comprising the mind with its faculties of perception, and the intellect sheath "vijñânamaya-kosha".
The causal body contains "ânandamaya-kosha", the sheath of bliss. It is composed of felicity and joy. It designates the subtlest level of human individuality. This sheath constitutes the last degree of submission or ignorance that takes the individual away from his true nature which is pure awareness of being.