Question

How is saturated air different from unsaturated air?

Answer 1

Saturated air is air that contains the maximum amount of water vapour it can hold at a given temperature, meaning its relative humidity is 100%. It cannot hold any more moisture, and any cooling will result in condensation. In contrast, unsaturated air contains less water vapour than its maximum capacity at that temperature, so it has a relative humidity less than 100% and can still absorb more moisture.