Universal health care (also called universal health coverage, universal coverage, or universal care) is a health care system in which all residents of a particular country or region are assured access to health care. It is generally organized around providing either all residents or only those who cannot afford on their own, with either health services or the means to acquire them, with the end goal of improving health outcomes.Universal healthcare does not imply coverage for all cases and for all people – only that all people have access to healthcare when and where needed without financial hardship. Some universal healthcare systems are government-funded, while others are based on a requirement that all citizens purchase private health insurance. Universal healthcare can be determined by three critical dimensions: who is covered, what services are covered, and how much of the cost is covered. It is described by the World Health Organization as a situation where citizens can access health services without incurring financial hardship. Then-Director General of the WHO Margaret Chan described universal health coverage as the "single most powerful concept that public health has to offer" since it unifies "services and delivers them in a comprehensive and integrated way". One of the goals with universal healthcare is to create a system of protection which provides equality of opportunity for people to enjoy the highest possible level of health. Critics say that universal healthcare leads to longer wait times and worse quality healthcare.As part of Sustainable Development Goals, United Nations member states have agreed to work toward worldwide universal health coverage by 2030.