A feedback loop is a fundamental element of systems theory, wherein a process is constantly updated in response to its output. This feedback, both positive and negative, can be used to help adjust the behavior of the system over time. Feedback loops can be seen everywhere and in many shapes, from complex robotic control systems to the more familiar biological processes. As an adaptive process, they are an essential tool for creating systems able to interact with and learn from their changing environment.

See also: choice making, complex system, game theory, hill climbing, reciprocal narrowing