Epidemic vs. Pandemic

Though many people get the two confused, pandemics and epidemics have a lot of overlap. An epidemic is an outbreak of a disease that spreads quickly and affects many people. A pandemic is a type of epidemic that occurs over a wide geographic range - 3 or more countries - and affects a high proportion of people. With these definitions in mind, it can be said that a pandemic can be a type of epidemic, however an epidemic is not a pandemic.