What information can be gained from the following diagram :

Explanation

This diagram explains all the three states of water and how the latent heat is used in the conversion of each state of water. This diagram also explains the physical properties of water and their interrelationship with one another.
The amount of heat energy required by ice (solid) to change into water (liquid), at its melting point without change in temperature is called as latent heat of fusion of ice.
The energy required to convert water (liquid) into steam (gas) at its boiling point without change in temperature, is called as latent heat of vaporisation of water.
When the water vapour or steam (gas) condenses back to water (liquid), heat is liberated. This heat is called latent heat of condensation.
The amount of energy required by water (liquid) to change into ice (solid), is called latent heat of solidification.