The structure-property-process correlation in polymers is a fundamental concept that ties together how the molecular arrangement influences the processing and properties of the end product. In this chapter, we will discuss the correlation and influence of the chemical structure, chain length, molecular weight distribution, and crystallinity of a polymer on its chemical, mechanical, thermal, optical, and electrical properties, and morphological characteristics. The polymer as raw material can be synthesized via different polymerization techniques, which will undergo several processes in the presence of fillers and other additives to manufacture the final product. The method and mechanism of polymerization directly impact the purity, architecture, chain length, and molecular weight distribution of a polymer. This chapter will provide information about polymerization and processing techniques, including polymer additives.