I frequently meet the references to voltage-regulators and voltage-controllers. However, looking at the specs I find them to perform the same function. Is there a difference between the two, or regulator/controller can be interchanged?
A voltage regulator produces a stable output voltage that has small variance over a range of load and input conditions.
A controller is a device that monitors and modifies the state of a dynamical system. A voltage controller could be constructed to track a signal, minimize undesired signal characteristics, or even act as a voltage regulator.