When a substance is heated, the energy supplied can do one of two jobs. It can raise the temperature, or it can change the state. Two quantities describe these two jobs, and you need to know the difference between them.
The specific heat capacity of a substance is the energy needed to raise the temperature of 1 kg of the substance by 1 °C. It is measured in J/kg °C. Water has a high specific heat capacity, so it takes a lot of energy to warm it up.
The specific latent heat of a substance is the energy needed to change the state of 1 kg of the substance without any change in temperature. It is measured in J/kg. The specific latent heat of fusion is for melting and freezing. The specific latent heat of vaporisation is for boiling and condensing.
So specific heat capacity is about a change in temperature, while specific latent heat is about a change of state at constant temperature. During a change of state the energy goes into the potential energy of the particles as they are pulled apart, not into making them move faster.
