Thermodynamics the branch of physical science that deals with the relations between heat, workor other forms of energy (such as mechanical, electrical, or chemical energy)and the properties of the systems.The system is a macroscopically identifiable collection of matteron which we focus our attention. Thus, it is importance to understand the principles and applications of the concepts of first and second laws of thermodynamics to various processes and cycles encountered in a system such as combustion of fuels and performance of engine,air power cycle in an air compressor, steam nozzle, refrigeration and air conditioning systemsand identify the methods for performance improvement. Thus, attending this course mechanical, Aeronautical, chemical engineers will gain theoretical knowledge of principle of thermodynamics and its application in real life and solve thermal related problems by adopting appropriate law and principle to analyse and interpret the performance of system.