5S is an improvement management tool used to discipline employees through daily audits and corrective actions. It involves five steps: 1) sorting out items to eliminate waste, 2) setting limits and systematizing through standardized locations for items, 3) shining equipment to maintain clean and sanitary work areas, 4) eliminating search time by organizing workspaces, and 5) setting standards and practicing discipline to sustain the first four S's. Proper implementation of 5S is crucial as it forms the basis for quality management programs and lean initiatives.