Entropy:Entropy is a measure of the disorder or randomness in a system. It quantifies how much energy has dispersed or how many different ways energy can be distributed within a system.
Carnot cycle: The Carnot cycle is an idealized thermodynamic cycle that consists of four reversible processes (two adiabatic and two isothermal) used as a benchmark for maximum efficiency in heat engines.
Heat engine: A heat engine is a device that converts thermal energy into mechanical work by exploiting temperature differences between a hot reservoir and a cold reservoir.