What is the dew point?

The dew point is defined as the temperature at which air becomes saturated with moisture, meaning that it can no longer hold additional water vapor, leading to condensation. When the air cools to this temperature, the water vapor within it begins to condense into liquid water, often forming dew or other types of moisture such as fog or clouds. This concept is crucial in meteorology and aviation because it helps in understanding weather patterns, humidity levels, and potential cloud formation, which are essential for flight safety and planning.

The other options relate to different aspects of atmospheric conditions, such as dry air and pressure, but they do not accurately capture the essence of what the dew point represents in the context of humidity and saturation.