A natural disaster is the highly harmful impact on a society or community following a natural hazard event. Some examples of natural hazard events include floods, droughts, earthquakes, tropical cyclones, lightning strikes, tsunamis, volcanic activity, wildfires. A natural disaster can cause loss of life or damage property, and typically leaves economic damage in its wake. The severity of the damage depends on the affected population's resilience and on the infrastructure available. Scholars have been saying that the term natural disaster is unsuitable and should be abandoned. Instead, the simpler term disaster could be used, while also specifying the category of hazard. A disaster is a result of a natural or human-made hazard impacting a vulnerable community. It is the combination of the hazard along with exposure of a vulnerable society that results in a disaster.

A hazard is a potential source of harm. Substances, events, or circumstances can constitute hazards when their nature would allow them to cause damage to health, life, property, or any other interest of value. The probability of that harm being realized in a specific incident, combined with the magnitude of potential harm, make up its risk. This term is often used synonymously in colloquial speech.