This document is the first unit of the Thermal Engineering course for the Mechanical Engineering program's third semester. It was prepared by Mr. Manoj Manik Charate and covers fundamental thermodynamics topics like heat, work, energy, enthalpy, and entropy. The contents include definitions of key terms, equations, and examples to calculate kinetic energy, potential energy, and changes in enthalpy and entropy. The goal is for students to apply the laws of thermodynamics to devices.