Other forms: subpopulations
A subpopulation is a specific small section within a larger group of people. All American middle-school students would be considered a subpopulation of U.S. residents.
Researchers studying a large population of people often break this group down into smaller, more manageable subpopulations. For example, when scientists examine the effects of a contagious disease, it's helpful to understand how it affects the subpopulations of older adults, infants, and people with preexisting conditions — as well as subpopulations including different genders, races, and ethnicities. Subpopulation uses the prefix sub-, "under," from the idea that subpopulations fall under the broader category of an entire population.