This document provides definitions and classifications related to removable partial dentures. It defines key terms like prosthodontics, prosthesis, and removable partial denture. It then describes Kennedy's classification system for partially edentulous arches, which categorizes them into four classes based on the location of edentulous areas. Applegate's rules are also covered, which provide guidelines for applying the Kennedy classification system. The primary purposes of removable partial dentures are outlined as well, such as preserving remaining teeth and tissues and improving functions like mastication, aesthetics, speech, and psychology.