The term "pandemic" comes from the Greek word "pandemos," which means "pertaining to all people" or "common to all the people." It combines "pan-" meaning "all" and "demos" meaning "people." The term was first used in the 1660s to describe diseases that affect an entire region or population broadly, distinguished from an epidemic by its much wider geographical spread, often crossing countries and continents. A pandemic is characterized not by the severity of the disease alone but by its extensive spread affecting large populations across multiple countries or regions.
In summary, it is called a pandemic because it refers to a disease outbreak that spreads broadly to "all people," emphasizing its vast reach across populations and regions. This广泛 geographical spread sets pandemics apart from epidemics or outbreaks, which are more localized.
