The word asana is usually translated as "pose" or "posture," but its more literal meaning is "comfortable seat."
In the Yoga Sutras, Patanjali describes asana as the third of the eight limbs of classical, or Raja Yoga. Asanas are the physical movements of yoga practice and, in combination with pranayama or breathing techniques constitute the style of yoga referred to as Hatha Yoga.
Tracy Hill, E-RYT 200
Pranayama is an in-depth science for expanding and channeling the life force, prana. "Pranayama" comes from two Sanskrit words: "prana", meaning the fundamental life force, and "yama" meaning to control. Pranayama is, therefore channeling or controlling the life force. "Pranayama" can also be seen as the combination of "pran", the life force, with "ayama", meaning expansion. In this sense pranayama expands the life force though all levels of our being, physical, psychological and spiritual.