Himidity is the amount of water vapor present in the air. Relative humidity is a measure of the amount of water vapor present in the air compared to the amount needed for saturation at a specific temperature
I'm assuming you're asking for the difference between specific humidity and relative humidty. If so... Relative humidity is exactly that: it is relative to the temperature. Warmer air can hold more...
Relative Humidity (RH), is how much water vapor is in the air at a certain time. Humidity, in my opinion, is just another way of saying how much water vapor is in the air.
HiThe problem with explaining humidity, is its relation ship to human life. Nobody is really interested until it affect them. The simplest way to describe relative humidity is at 100% the human body...