What does the term “cabin pressurization” refer to?

The term "cabin pressurization" specifically refers to the process of maintaining a safe and comfortable environment within the aircraft cabin at high altitudes. As the aircraft ascends, the external atmospheric pressure decreases significantly, which can lead to various physiological issues for passengers and crew if the cabin were not pressurized.

To counteract this, pressurization systems regulate the cabin environment by increasing the air pressure inside the cabin to levels that are conducive to human comfort and safety. This typically involves using pressurized air from the engines or auxiliary power units. The pressurization allows people to breathe normally and prevents altitude sickness, which would otherwise occur at high elevations.

While adjusting the cabin temperature, replacing the air, and creating a vacuum are important aspects of maintaining overall cabin conditions, they do not specifically define the process of cabin pressurization, which is focused primarily on maintaining an adequate pressure level to ensure a safe and comfortable experience for those onboard.