This book is an introduction to polymers and focuses on the synthesis, structure and properties of the individual molecules that constitute polymeric materials. It approaches polymeric materials from a molecular basis on the belief that there is a common core of knowledge and principles concerning polymer molecules that can be set out in an introductory work. Subjects treated include an introductory overview of synthesis, an introduction of the concept and definition of molecular weight and its distribution, experimental methods for measuring molecular weight, a more detailed view of polymerization including kinetics and mechanism, and the three-dimensional architecture of polymers as determined by conformation and stereochemistry. The statistical description of the conformational disorder of the molecules is covered and then built upon in treating rubber elasticity and polymer solutions.