Ujjayi translates as victorious. The chief characteristic of this pranayama is the slight hissing noise created by partially closing the glottis of the throat. Familiar to many yoga practitioners.
However, full Ujjayi pranayama is more than just the sound, involving a further technique. Helpful for vata imbalance and very calming to the nervous system.
Skill in Ujjayi is helpful for all other pranayamas.