Final answer:
Population density is the term that describes the relationship between the number of inhabitants and the area they occupy, which is a fundamental concept in demography.
Step-by-step explanation:
The relationship between the number of inhabitants and the area they occupy is known as population density. Population density is a crucial concept in demography and human geography, as it reflects the average number of individuals in a population per unit of area or volume.
For example, if a population of 100 insects lives in an area of 100 square meters, the density is 1 insect per square meter, whereas in a space of 1 square meter, the density skyrockets to 100 insects per square meter, indicating a much more crowded environment that could impact the health and interactions within the population. Geographers and ecologists often examine population density to understand better how species adapt to their environment, compete for resources, and interact with each other.