Cybernetics is a field of systems theory that studies circular causal systems whose outputs are also inputs, such as feedback systems. It is concerned with the general principles of circular causal processes, including in ecological, technological, biological, cognitive and social systems and also in the context of practical activities such as designing, learning, and managing.
Principle diagram of a cybernetic system with a feedback loop
Norbert Wiener
Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to feed back into itself. The notion of cause-and-effect has to be handled carefully when applied to feedback systems:Simple causal reasoning about a feedback system is difficult because the first system influences the second and second system influences the first, leading to a circular argument. This makes reasoning based upon cause and effect tricky, and it is necessary to analyze the system as a whole. As provided by Webster, feedback in business is the transmission of evaluative or corrective information about an action, event, or process to the original or controlling source.
Feedback can give rise to incredibly complex behaviors. The Mandelbrot set (black) within a continuously colored environment is plotted by repeatedly feeding back values through a simple equation and recording the points on the imaginary plane that fail to diverge.