Disasters are defined as events that seriously disrupt society and cause widespread human, material, or environmental losses beyond what people can cope with using their own resources. Disaster risk refers to the likelihood of harm from hazards due to community or environmental vulnerabilities. Natural disasters originate from natural forces like volcanoes, earthquakes, typhoons, and fires, while human-made disasters are caused by human actions like war, bioterrorism, and industrial accidents involving nuclear power or hazardous materials.