This document defines and classifies different types of fractures, including closed and open fractures. It describes the stages of fracture healing and bone repair. Various fracture classification systems are outlined, including the Gustilo-Anderson system for open fractures, the AO/Mueller system, and Salter-Harris classification for pediatric fractures. Key stages of fracture healing include hematoma formation, inflammation/proliferation, callus formation, consolidation, and remodeling.