Change in state and latent heat

Define latent heat of fusion of ice and latent heat of vaporisation of steam.

What is latent heat ? Give its units. With the help of a suitable graph, explain the terms latent heat of fusion and latent heat of vaporisation.

What is the unit of latent heat?

What do you mean by latent heat of fusion and latent heat of vaporisation? What are its units and dimensions?