This document discusses key concepts related to disaster readiness and risk reduction. It defines a disaster as a sudden event, either natural or man-made, that causes widespread harm and damage. Disasters affect at least 20% of a population or destroy 40% of their livelihoods. The document distinguishes between natural disasters, caused by environmental processes, and man-made disasters caused by human actions. Examples of hazards that can lead to disasters are provided. Finally, disaster risk is defined as the potential losses to lives, health, livelihoods or assets that could result from a hazardous event.