Pranayama is a Sanskrit word formed by two words.''Prana'' which means a subtle life-force which gives energy to the mind and body,and ''Ayama'' which signifies the voluntary effort to control and direct prana.
Pranayama therefore is the process by which the ''prana'' is controlled by regulating the breathing voluntarily.This involves the temporary pause or interval in the movement of the breath.The techniques of pranayama provides the method whereby the life-fource can be activated and regulated in order to go beyond one's normal boundaries or limitations and attain a higher state of energy.
During the respiration process,we breathe in or inhale oxygen into the body,this then goes through our body systems in a form of energy to charge our different body parts.When we exhale carbon dioxide,it takes away all the toxic wastes from our bodies.Through the practice of pranayama,the balance of oxygen and carbon dioxide is achieved.Absorbing ''prana'' through breath control links our body,mind and spirit.
In pranayama practices there are four important aspects of breathing which are utilised.These are,'Pooraka' or inhalation,'Rechaka' or exhalation,'Antar Kumbhaka' or internal breath retention and 'Bahir Kumbhaka' external breath retention.The various practices of pranayama,involves techniques which uses these four parts of breathing.
According to the great sage Patanjali, pranayama is actually breath retention I quote.''Pranayama is the cessation of the movement of inhalation and exhalation''(Soutra 49).Inhalation and exhalation are methods of inducing retention.Retention is the most important because, it allows a longer period for the assimilation of ''prana'', just as it allows more time for the exchange of gasses in the cells of the body (oxygen and carbon dioxide).Therefore through the breath and pranayama,''prana''(life-force) and consciousness are vitally linked.