A regulator is a device or mechanism designed to ensure stability in a system by controlling variables in accordance with a predefined target, such as voltage, pressure, or speed. From mechanical governors to legal frameworks, the concept appears in both technical and socio-political domains. John Stuart Mill referred to custom as a "habitual controller" in economics, while U.S.
legislative documents highlight regulatory power in finance. Sir John Salmond associated "regulator" with order and governance, distinguishing it from ideas of justice. These viewpoints emphasize the regulator's function as a stabilizing element, whether in machinery or institutional structures, demonstrating its broad applicability in managing complex systems.