Tidal breathing is the term for inhaling and exhaling while you are relaxing.
The depth of inspiration and the end point of passive exhalation at functional residual capacity (FRC), the point at which the inward elastic rebound of the lungs balances the outward elastic recoil of the rib cage (RC), dictate the range of tidal breathing.
Lung disease not only can modify the typical character of breathing, but it can also generate change during a series of breaths, even though tidal breathing is frequently maintained within a very limited range in a person who breathes quietly and does not have lung disease.