Is control a type of negative feedback?
Control is not a type of negative feedback. "Control" is a set of techniques that allow us to manipulate engineered systems automatically, and some of these techniques use negative feedback.
Negative feedback refers to a type of control technique where the control action is in the opposite direction from the error. For example, in the cruise control system when the vehicle is too slow, the response of a negative feedback law would be to speed up. This is opposed to positive feedback, where the control action is in the same direction as the error. Positive feedback systems exhibit unstable behavior; the most common example is the high-pitched humming in a sound system when a microphone is placed directly in front of a speaker.
--George Hines 20:46, 1 October 2007 (PDT)