Saturation Temperature (boiling point) - The temperature for a corresponding Saturation Pressure at which a liquid boils into its vapor phase. The liquid can be said to be saturated with thermal energy. Any addition of thermal energy results in a phase change.

If the pressure in a system remains constant (isobaric), a vapor at Saturation Temperature and Pressure will begin to condense into its liquid phase as thermal energy (heat) is removed. Similarly, a liquid at Saturation Temperature and Pressure will boil into its vapor phase as additional thermal energy is applied.