Refers to the total energy of a system.

The internal energy refers to the total energy of a system. The enrgies are kinetic energy and potential energy of the system that makes up the whole energies of the system.

Enthalpy refers to the total energy of a system. Enthalpy is basically a thermodynamic unit of measurement that determines the total heat content of a system. This means that all energy is included in the measurement - the energy used to make the system, the energy of the system, and the energy it uses to keep the environment separate from the system.