As per the above shloka from Patanjali Yoga Sutra, by practicing
Pranayama the ability to perceive, to know the reality is intensified. The mind
is trained and made capable for the process of dharana. Since the mind becomes
steady and peaceful after the practice of Pranayama, it becomes suitable and
capable to concentrate on a particular object. Such 'one-pointedness' or
'ekagrata' is a pre-requisite for dharana. To know more read: