The concept of the five koshas (sheaths) is mentioned in the Taittiriya Upanishad. The koshas are described as five layers encasing the Pure Consciousness (Purusha) or Self (atman). In Sanskrit, they are called annamaya kosha (food sheath), pranamaya kosha (sheath of prana or life), manomaya kosha (mind sheath), vijnanamaya kosha (knowledge or wisdom sheath) and anandamaya kosha (bliss sheath).
Annamaya Kosha
Annamaya kosha literally means food sheath. It is the physical body made of matter. It is what one can see, hear, smell and touch of another person. This kosha is dependent on the following sheath of life force and will disintegrate as soon as life or prana has left the body. It is related to the mineral stage of evolution.
Pranamaya Kosha
This is the layer of prana (life force, energy) that makes the otherwise dead body alive. It is intimately connected with the breath, but also with the processes of digestion and growth and is related to the plant stage of evolution.
Manomaya Kosha
Manas is Sanskrit for mind. This kosha is made up of feelings, thoughts and emotions as well as memory and imagination, comprising both faculties of manas (mind) and chitta (subconscious mind and memory). The manomaya kosha is related to the animal stage of evolution.
Vijnanamaya Kosha
Vijnana means knowledge or wisdom. This sheath is what sets human beings apart from animals which may have feelings, emotions and even thoughts and memory just like us. But only human beings have the faculty of discernment between right and wrong, eternal and illusory. It is transpersonal and transcends mere rational thinking. This kosha also includes having an ego, a sense of identity or “I-Am-ness” (ahamkara).
Anandamaya Kosha
This is the bliss-filled sheath (ananda = bliss, maya = filled with). This kosha is the finest, thinnest veil covering the Self (atman) and could also be called the level of the soul. On this level, there is a strong awareness about the oneness of the individual and the Absolute. However, there is still some separation and unless this sheath is transcended, individual existence and therefore rebirth, will continue. This kosha is also called the causal body and is said to contain the essence of an individual soul’s experiences of countless lifetimes and stage of spiritual evolution.
Beyond the Koshas
Beyond the koshas, encased yet untouched by them, is the Self (atman) which is pure spirit and which is not different from the Absolute Reality (Brahman). Unlike the five koshas, the Self is nothing that can be perceived but is Pure Consciousness itself, on which all the koshas depend. (See also Meditations on the Five Koshas). The realization of the Self is the aim of the all the Yoga paths, especially Yoga Meditation such as the Neti-Neti approach of Jnana-Yoga and the practice of Self-Inquiry.