This chapter focuses on the essential aspects and the workings of the process of iron ore sintering intending to appreciate the technical aspects. The chapter begins with an account of the sintering process itself and describes the procedure of converting fine iron ore particles into blast furnace feed sinters. It investigates the bonding principles of particles and agglomeration which explains how smaller-sized individual iron ore particles are joined together to form bigger-sized agglomerates when heated. The chapter also discusses the effects of various parameters such as temperature, moisture content, and the chemical aspects of the feed constituents on the kinetics and the final product of sintering. To emphasize the complexity of the process, the mechanisms and reactions that occur during sintering, including heat and chemistry, are also explained. The chapter therefore is, in a way, complementary to the previous one and lays the foundation for topics that are more scientific and technological that are addressed in the subsequent chapters.