Question

What is an epidemic and a pandemic?

Answer 1

A pandemic (from Greek πᾶν pan "all" and δῆμος demos "people") is an epidemic of infectious disease that has spread through human populations across a large region; for instance multiple continents, or even worldwide.

Answer 2

An epidemic is a spread of a disease that affects more people than is usual for the locality or one that spreads to areas not associated with the disease.

a pandemic is an epidemic of worldwide proportions