Thermodynamics is one of the subjects that is rooted to our daily life, starting from boiling water in the morning, the operation of cars, to the melt of ice in our cold drinks. This course aims to relate students to the concept of states and equilibrium. In addition to the phenomenological equations, the idea of microstates and statistical thermodynamics will be introduced to explain entropy. Furthermore, applications of thermodynamics in heat engines, multicomponent systems, phase diagrams, and chemical equilibrium, as well as the concept of identifying a system state from the first principle will be illustrated.