What is enthalpy and why is it important in thermodynamics?

Enthalpy (H) is a thermodynamic property defined as H = U + PV, combining internal energy (U) with flow work (PV). It represents the total heat content of a system at constant pressure. Enthalpy is extensively used in analyzing steady-flow devices like turbines, compressors, and heat exchangers because it simplifies energy balance calculations for open systems.