Cabin pressurization is the process of maintaining a safe and comfortable air pressure inside an aircraft during flight. As an airplane ascends, the outside air pressure decreases, which can make it difficult for passengers and crew to breathe. To counter this, aircraft are equipped with systems that pump in air and regulate the cabin pressure, ensuring it remains at a level similar to that found at lower altitudes. This pressurization is crucial for passenger safety and comfort, as it helps prevent altitude sickness and allows for normal physiological functions. The systems are designed to automatically adjust pressure levels, providing a stable environment throughout the flight.