Yoga sutra I.12 abhyasa vairagyabhyam tannirodhah

“Practice and detachment are the means to still the movements of consciousness”

To practice yoga is to still the movements of our consciousness.

When we practice asana we focus the eyes on a dristi point specific for a pose.  Our mind follows our eyes, or the parts of the body being engaged, or our breath.  If the mind, hence our consciousness, fluctuates from these we are not practicing yoga.

When we practice pranayama our consciousness is on our breath. When we practice pratyahara our consciousness is turned inward detaching from our senses.  When we practice dharana our consciousness is focused, concentrating on an object or thought.

When we practice dhyna we are our consciousness without fluctuation.

When we are not practicing yoga we must detach from our emotions, from stimuli and the interactions we encounter.  When we are detached from the events we experience the mind is engaged in each moment of the experience, and therefore not thinking of or fluctuating between the past or future.  So if you are conversing with someone you are either talking or listening, but your mind is fully engaged in this act, therefore the consciousness is still.

When we practice any of the limbs of yoga we train our minds to detach from everything but this act of yoga.  We also come to understand what we gain through detachment.  By practicing regularly we become skilled in detachment and the mind becomes calm and our consciousness becomes steady moment by moment.