Literally means ‘to stretch that which is everywhere’. These breathing exercises consciously control the prana within.
Lengthening the inhalation increases the prana absorbed. Directing prana via certain currents (vayus) through the body clears energetic blockages (samskaras and granthis). Thus kundalini shakti can travel uninhibited through all 72,000 nadis and eventually via sushumna nadi to bring enlightenment (Samadhi). These practices are deeply restorative and balancing and available even to the weakest of sadhakas. The beauty of vinyasa is that we practice ujjayi pranayama without conscious effort.
As we inhale our diaphragm expands downward forcing prana in apana vayu. We counterbalance this by externally moving skyward e.g. Urdhva hastasana. Exhaling the opposite occurs; the breath moves upward via prana vayu and so we externally move toward the earth e.g. Uttansasana.
The use of bandhas (root locks) allow us to circulate air to specific regions and organs of the body:
moola bandha : perineum
uddiyana bandha: stomach
jalandhara bandha: throat
Concentrating on the inhale and exhale allows outside distractions to fall away and awareness of our inner self occurs.