water vapor
is the gaseous phase of water.
humidity
a quantity representing the amount of water vapor in the atmosphere or a gas.
evaporation
is a type of vaporization of a liquid that occurs from the surface of a liquid into a gas phase
condensation
water that collects as droplets on a cold surface when humid air is in contact with it.
relative humidity
the amount of water vapor present in air expressed as a percentage of the amount needed for saturation at the same temperature.