A pandemic is an outbreak of a disease that spreads across multiple countries or continents, affecting a large number of people. Unlike a local outbreak, which may only impact a small area, a pandemic can reach global proportions. For example, the COVID-19 pandemic, caused by the coronavirus, affected millions worldwide and changed daily life for many. During a pandemic, health organizations like the World Health Organization (WHO) work to control the spread of the disease and provide guidance to governments and communities. People are often encouraged to practice good hygiene, such as frequent handwashing and wearing masks, to help prevent transmission.