Enthopy
S, measure of energy of the thermodynamic system. Includes internal energy and require to create a system, and the amount of energy required to make room for it by displacing its environment and establish its volume and pressure.
isentropic process
adiabatic and reversible
Adiabatic
no heat transfer (Q=0)
Enthalpy
Enthalpy (H) is a measure of the total energy of a thermodynamic system. It includes the internal energy, which is the energy required to create a system, and the amount of energy required to make room for it by displacing its environment and establishing its volume and pressure.