What is the delta H in the Gibbs free energy equation?

In the Gibbs free energy equation, ΔG = ΔH - TΔS, ΔH represents the change in enthalpy of a system. It reflects the total heat content and energy changes during a chemical reaction or phase transition at constant pressure. A negative ΔH indicates an exothermic reaction, while a positive ΔH indicates an endothermic reaction. This term is crucial in determining the spontaneity of a process along with the entropy change (ΔS) and temperature (T).