Thermodynamics is a branch of Physics which deals with the equilibrium, energy and its transformation from one form to another. It deals with the relationships between heat and work, and the properties of the system in equilibrium. Historically, Thermodynamics originated as a result of man’s endeavor to convert heat into work. The principles of thermodynamics are summarized in the form of four laws that fall within the constraints implied by each which are zeroth law of thermodynamics, first law of thermodynamics, second law of thermodynamics and third law of thermodynamics.Thermodynamics studies the behavior of Energy. Energy exists in many forms, such as heat, light, electrical energy, chemical energy etc. Energy is the ability to bring about change or to do work. It deals with various macroscopic variables like pressure, temperature, internal energy etc. The results of thermodynamics are useful for other branches and fields of Physics and engineering like mechanical, chemical, physical, biomedical, geology, psychrometrics, statistics etc.Thermodynamics is the study of Heat and Thermal energy. It is a science which studies various interactions amongst energy, heat, work and temperature, with matter that brings about significant changes in the macroscopic properties of a substance that are measurable. It is basically a phenomenological science based on certain laws of nature which are always obeyed and never seen to be violated.