The volume and pressure of air (or any gas) are related.
A bigger volume of air has to be moved farther.
It's surrounded by a large volume of air isn't it?
This allows a much greater volume of air to be displaced.
It is the volume of air that flows through the port in a given time.
The tire is generally wide and thick, giving a large air volume.
One treatment strategy was to push large volumes of air into patients' lungs, at high pressure.
If the volume of air involved is relatively small, incineration works fine.
The actual volume of air taken into the lungs with either means varies.
A larger volume of air has a lower average humidity as the process proceeds.