The saturation vapor pressure is the pressure at which water vapor is in thermodynamic equilibrium with its condensed state. At pressures higher than vapor pressure, water would condense, while at lower pressures it would evaporate or sublimate.
The pressure at which water vapor is in balance with its liquid form is known as the saturation vapor pressure. At pressures higher than this value, condensation will occur; at lower pressures, evaporation or sublimation will happen.