Enthalpy is t a measure of heat transfer. It does not refer to a process. Rather, it refers to a state of the system.
Enthalpy is a measure of energy in the system , which is the form of energy to consider when the system is closed and operating at constant pressure (rather rare) or when the system is open, with inflows and outflows (rather common).
The expression for enthalpy H is
H = U + PV
in which U is the internal energy and PV (multiplication of pressure by volume) is a correction to take into account the effect of pressure work.
Study 40% syllabus and score up to 100% marks in JEE