Enthalpy
If a system is fully closed and the system pressure held constant, the amount of heat released or absorbed, is termed enthalpy. Enthalpy can be thought of as the amount of heat (sensible and latent) a substance contains.
Tip - removing the word ‘enthalpy’ and replacing it with ‘energy’ sometimes helps with understanding the meaning of enthalpy.
Example 1
The amount of sensible heat required to raise a given mass of liquid from its freezing point to its boiling point (saturation temperature) is termed the enthalpy of a liquid at saturation temperature. Replacing the word ‘enthalpy’ with ‘energy’ gives ‘energy of a liquid at saturation temperature’. This term describes the total amount of sensible heat required to raise a given mass of liquid from its freezing point to its boiling point i.e. the total amount of energy required to raise a given mass of liquid from its freezing point to its boiling point.
Example 2
The amount of latent heat required to turn a given mass of saturated water (water at its boiling point) into dry saturated steam, is termed enthalpy of vaporisation. Replacing the word ‘enthalpy’ gives ‘energy of vaporisation’ (the amount of energy required to evaporate the saturated water). This term describes the total amount of latent heat required to turn a given mass of saturated water into dry saturated steam i.e. the total amount of energy required to turn a given mass of saturated water into dry saturated steam.
Additional Resources
https://en.wikipedia.org/wiki/Enthalpy
https://www.britannica.com/science/enthalpy
https://www.westfield.ma.edu/PersonalPages/cmasi/gen_chem1/Energy