Transitions between solid, liquid and gaseous phases involve a specific amount of latent heat absorbed or released.
If heat is added at a constant rate to mass of a solid, like ice, to change it to liquid water, it is called latent heat of fusion. The heat required to convert liquid to gas is latent heat of vaporization.
In the phase change from gas to liquid, there is a release of latent heat of condensation. Phase change from liquid to solid releases latent heat of solidification.