definition
entropy is a measure of the randomness or the extent of disorder of a chemical process.
enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.
measurement units:
entropy is measured in joule per kelvin (jkโปยน) whereas enthalpy is measured in joule per mole (jmolโปยน)
requirements:
entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.
in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.