A pandemic is defined as an outbreak of a disease that occurs on a global scale, affecting a large number of people across multiple countries or continents. Pandemics are typically caused by new pathogens, such as viruses or bacteria, that can spread easily from person to person. They often lead to significant social, economic, and public health impacts due to the strain on healthcare resources. Public health measures, including vaccination, social distancing, and communication strategies, are essential in managing pandemics and reducing transmission.