Functional response is a term used in ecology to describe the relationship between a predator's feeding rate and the density of its prey. It represents the predator's ability to capture and consume prey as the prey density varies. Functional response is typically studied in experiments where predators are exposed to different densities of prey and their feeding rates are measured. The shape of the functional response curve can vary depending on factors such as predator behavior, prey vulnerability, and environmental conditions. Understanding functional response can provide insights into predator-prey interactions, population dynamics, and community structure.