What is a Kosha?
A kosha is like a sheath. There are five, (meaning pancha), so they are known collectively as the pancha koshas. They are an integral part of our being. An integral part of our spiritual journey. We can relate easily to these sheaths, as being like "bodies", although, strictly speaking, they are not. Each kosha has the word "maya" as part of it. Maya is often translated as illusion. And, illusion can have many meanings. Sometimes it refers to spiritual knowledge which reveals illusion. As one journeys through the koshas, much of what we believe, falls away, as we gain more and more spiritual wisdom. But, it is worthwhile knowing that maya can and does, have several meanings.
The physical body kosha
We have a physical sheath, which is our physical body. Although it is only one of our bodies, it is the one which people generally relate to as being the sum part of us, our whole being in this existence, whereas Vedanta says that we have a fivefold existence, and that fivefold is about the pancha koshas.
The physical sheath is known as the annamaya kosha. According to Gitananda Yoga, it is comprised of cells, cells being the maya aspect in this case, which are made from food, which is the anna part. Plus, the different parts of the body feed itself. The physical body is a complex working organism made up of so many aspects which are interdependent. Sometimes in yoga, the annamaya kosha is translated as the food sheath, and that we must eat special food to sustain it. Which is quite logical, and correct. Many translate it as veganism, others as eating special powders for health. However, if you remember that our body is part of nature, and the best food for us is untampered food from nature, you will be feeding the annamaya kosha as it is meant to be fed.
It is quite usual for yoga practitioners to become vegetarian, it just happens. However, the best food for your annamaya kosha, will always be the natural food which suits your own body, best.
We are not just the physical body
How do we come to realise that we are not just our physical body? And not just our thoughts and desires, likes and dislikes? Having the koshas reveal themselves is one of the primary ways. And no amount of talking, reading, nor musing, will have that happen. And when we have an awakening of the next kosha, the pranamaya kosha, we do indeed uncover the realisation that the physical body is not our only "body". We shed yet another illusion. To be honest, having the pranamaya kosha "wake up", "reveal itself", is a big happening, and it is not unusual for a lot of illusion to release, then go away, when this momentous event takes place.
The prana/life-force body
As one progresses through the spiritual realms, one's energy changes. It becomes more intense. Our body seems to rejuvenate. How does this happen? If we are practising yoga, the asanas (postures) do indeed rejuvenate our body, and the breathing (pranayama) does give us sustained energy, and increased mental faculty. And meditation reduces stress. These three aspects of yoga, together definitely alter our physical and mental energy. They also increase our spiritual energy. What we are after, for a pranamaya awakening, is to build up our prana, or life-force, levels. It is generally accepted that we absorb prana via the breath. Life-force is indefinable. It is the spark, or sparks, of energy, contained within every living thing, especially within the air that we breathe. Those little dots of bright light that are easy to see on a sunny day? They are prana, and if you watch, you will see that they move. Like a dance.
Prana is not static within us. It has a role to play. On the annamaya/physical body level, it does indeed “feed” the body. The more prana that our body has, the more vital, and healthier, we are. When we eat food that has absorbed life-force from the earth, such as root vegetables, and when we eat food that has absorbed prana from the sun’s rays, such as vegetables and fruit, we are also “eating” life-force. When we drink clean running water, that too contains life-force.
So, on a purely practical level, we can say that the annamaya kosha and the pranamaya kosha, work in tandem. Just as without air, we die, without prana, we cannot exist on this earthly plane.
However, the pranamaya kosha is far more than all this.