The words of the sutra

• Śvāsa means inhalation.
• Praśvāsa means exhalation.
• Gati means movement or flow.
• Vicchedaḥ means regulation or deliberate control.

Patanjali defines pranayama as the conscious regulation of the breath. Before discussing the mind, meditation, or deeper states of awareness, Patanjali begins with something immediate and observable: control over the inhale and exhale.