koshas

Koshas are theoretical study of understanding one’s body in truest sense. Each of the koshas’ exhibit certain characteristics. Layer by layer, self is exposed in a hierarchal manner.

The five progressively subtler bodies that compose our personality are described in a yoga classic called the Taittiriya Upanishad:

1. Human beings consist of a material body built from the food they eat. Those who care for this body are nourished by the universe itself.
2. Inside this is another body made of life energy. It fills the physical body and takes its shape. Those who treat this vital force as divine experience excellent health and longevity because this energy is the source of physical life.
3. Within the vital force is yet another body, this one made of thought energy. It fills the two denser bodies and has the same shape. Those who understand and control the mental body are no longer afflicted by fear
4. Deeper still lies another body comprised of intellect. It permeates the three denser bodies and assumes the same form. Those who establish their awareness here free themselves from unhealthy thoughts and actions, and develop the self-control necessary to achieve their goals.
5. Hidden inside it is yet a subtler body, composed of pure joy. It pervades the other bodies and shares the same shape. It is experienced as happiness, delight, and bliss.

Consciousness in beings flows in 5 layers of the body to reach the Atman (or Self, according to Vedanta literature). These five layers in yogic tradition or ayurveda are called koshas.