Wars: Armed confrontation between two or more States, carried out by the respective armed forces, and regulated by international law. ICRC

Water supply: Water supply by utility companies, commercial enterprises, community or individual efforts, usually through a system an aqueduct system. WHO

Water service interruptions: Cuts or suspension of water service. Severe interruptions are considered when people are subjected to water service cuts for more than two weeks in a row, per month. ILO

Water treatment plants: A set of engineered structures and systems in which water is treated to make it fit for human consumption. CDC

Water, sanitation, and hygiene in emergencies: Humanitarian actions in the face of serious collapses of basic services, as a consequence of humanitarian emergencies, which leave populations with or little or no drinking water and basic sanitation facilities. UNICEF

WHO Grade 2 and 3 Emergencies: Classification for severe or very severe emergencies. Both grades cover events in one or more countries with moderate or severe public health impacts that require a proportionate WHO response. WHO

Working Group on HIV/AIDS in Emergency Settings: Agency created to support efforts to address the needs of people with HIV living in emergency situations.  UNAIDS

World Food Programme (WFP): UN agency as a humanitarian organization in the fight against hunger, and the provision of food assistance in emergencies to improve nutrition and build resilience in the populations of affected countries. WFP

World Health Organization (WHO): An organization that is part of the UN specialized in prevention, promotion and intervention policies in health at a global level to eradicate diseases, ensure the development of health systems, and provide humanitarian assistance in cases of emergency. WHO

World Humanitarian Summit: Global meeting to commit to universal humanitarian principles, initiate joint action to help countries and communities better prepare for crises and focus humanitarian action on best practices to alleviate the suffering of people in war, disaster, or complex emergencies. WHS