Population density differs from population size in that population size refers to the total number of individuals in a population, whereas population density refers to the number of individuals per unit area or volume. Population size is a raw count of all organisms present, while population density measures how crowded or dispersed those individuals are within a specific area. For example, a population size might be 1,000 animals in a forest, but the population density would be the number of animals per square kilometer in that forest, indicating how densely they are packed in the space.

Key Differences

• Population Size: Total count of individuals in a population without regard to area.
• Population Density: Number of individuals per unit area or volume, showing distribution intensity.
• Population density helps understand resource demand, competition, and living conditions, while population size informs about the scale of a population.

Example to Illustrate

• 1,000 rabbits in a forest represent population size.
• If the forest is 100 square kilometers, population density is 10 rabbits per square kilometer.

Thus, population size and density measure different aspects of population and provide complementary insights.