what does population density mean? i searched it up on the dictionary. com , but i still do not understand

Population density counts the number of people per square mile (or square kilometer).

Deserts and high mountainous regions have very few people so they have a low population density. Big cities, where hundreds of people may live in the same apartment building, have a high density population.

Check this U.S. population density map. Notice that the darkest colors represent the areas with the highest densities. The lightest colors are used for low-density population.

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