Mastery of Breath means mastery of Life
Prana means «breath», «wind» or «vital energy» and Yama means «regulation/restriction» or «mastery». Also, Ayama can mean «lengthening» or «without restriction». Pranayama can be understood as the mastery of our life breath and the cessation of its disturbances.
Through the breath, we are all intimately connected to something much greater than our senses can grasp, something overwhelming to our limited mental awareness. All in our life depends upon breathing and ultimately brings us back to this thread which extremities are found at birth and death.
Achieving breath mastery allows one to master its inner states on all levels; physically or mentally. It allows mastery over one's attitude therefore, generating accurate results.
The greatest secrets of this practice are found in what is called the «breath beyond the breath».