Question

What is latent heat of fusion and latent heat of vaporisatio​

Answer 1

In the case of the latent heat of fusion it is the heat required to change a substance from a solid (ice) to a liquid (water) or vice versa while the latent heat of vaporization from a liquid (water) to a gas (steam) or vice versa

Answer 2

The amount of heat energy absorbed at constant temperature by unit mass of a
solid to convert into liquid phase is called the specific latent heat of fusion.
The amount of heat energy absorbed at constant temperature by unit mass of a
liquid to convert into gaseous phase is called the specific latent heat of vaporization.