This lecture covers the fundamentals of polymer chemistry, including the definition of polymers, polymerization mechanisms, molecular weight control, and the influence of tacticity on polymer properties. It also discusses the crystallization behavior of polymers, the glass transition temperature, and strategies to control molecular weight. The lecture delves into the classification of polymers based on their chemical structure, the phases of polymers in the solid state, and the factors influencing the glass transition temperature. Additionally, it explores copolymers, block copolymers, and the glass transition temperatures of polymer blends. The session concludes with an overview of molecular weight distribution and the importance of controlling molecular weight in polymer synthesis.