This document discusses the fundamentals of thermodynamics. It introduces thermodynamics as the branch of engineering science dealing with the movement of fluids through the application of heat. It then defines thermodynamics processes as the successive states a system passes through during a change in state. The document goes on to summarize the four main laws of thermodynamics: zero law regarding systems in thermal equilibrium, first law regarding the conservation of energy, second law regarding heat flow from hot to cold bodies, and limitations of the second law such as the impossibility of converting all heat into work.