Prana - Life force - Breath - Energy?
Prana is a Sanskrit word that translates as 'vital life force'. It is the universal principle of energy or life force. It is the sum total of all energy that is manifested in the universe. All the forces in nature, powers which are hidden in men and which lie everywhere around us.
Prana is the link between the subtle and the physical body.
Okay, what does this actually mean in a way I can understand?
Our outermost layer, the physical body, is what we tend to associate with most because it's tangible - we can see it, feel it, touch it, and therefore rationalize it. My skin is dry. My hair is getting longer. I have a graze on my knee.
Less tangible, but no less real, is the energy that exists within and around the physical body. In Yoga, we call this energy Prana, the vital life force that sustains everything. You may even have heard of it as Qi, Chi and Ki in other eastern practices.
In our physical body, blood flows through veins, capillaries, and arteries. In our energy body, Prana flows through energy pathways called Nadis. Nadi translates as flow, channel.
Prana rides on the breath, so when we breathe in, we take in Prana. When we expand the breath and improve the quality of it, we are expanding and improving the quality of this vital life force within and around us. This is exactly what yoga breathing techniques, or Pranayama, are designed to do.