This document discusses organizational change and related concepts. It defines organizational change as planned or unplanned transformations in an organization's structure, technology, or people. It distinguishes between first-order changes that are continuous, and second-order changes that involve major shifts. It also discusses the characteristics of change, reasons for change, levels of change, and sources and tactics for overcoming resistance to change. Common change management approaches like Lewin's three-step model, action research, and organizational development are summarized.