While speaking of disaster risk reduction, mitigation, and management, use of right terminology is critical to ensuring effective communication between all players. The chapter, while introducing the commonly used terms such as threat, danger, hazard, disaster, crisis, calamity, catastrophe, and cataclysm, throws light on their respective origins and uniqueness. The meaning and importance of the twin terms—rumor and panic,and of the trinity—hazard, vulnerability and risk, are explained. While the boundary between natural and man-made disasters is obscure and disputed, the thin line that divides the success of disaster management from the failure of disaster mismanagement is almost always visible. The point is made through cartoons and illustrations.