This document summarizes the changes between the fifth and sixth editions of the Project Management Body of Knowledge (PMBOK). It notes that the PMBOK has evolved significantly since 2013 and must be updated every four to five years. The sixth edition features several changes including adding new knowledge areas, consolidating and renaming some processes, and reorganizing some content. For example, the human resource management area was renamed to resource management and some processes were moved between knowledge areas like risk and procurement management.