Density-dependent factors are biotic elements that intensify as population density increases.

Density-independent factors are usually abiotic events, such as drought, fire, hurricanes, or volcanic eruptions, that affect a population by the same proportion regardless of how dense it is.

An ecological footprint is the measure of the amount of land and water area required to provide all resources a population consumes and absorb waste and emissions (e.g., CO₂ absorption by forests)

Human carrying capacity is the maximum number of people Earth can support indefinitely, given current technology and lifestyle choices.

Limiting factors are conditions that restrict population growth.

Negative feedback loops are processes where the output of a system acts to reduce or reverse changes, helping the system maintain stability.

Overshoot is when a population's demand on its environment exceeds the carrying capacity. It can only be temporary, and the degradation it causes lowers the carrying capacity further.