A feedback mechanism is a process that uses the conditions of one component to regulate the function of the other. It is done to either increase or dampen the change in the system. When the process tends to increase the change in the system, the mechanism is known as positive feedback. Negative feedback is when the process seeks to counter the change and maintain equilibrium.
Feedback is part of a cause-and-effect loop where information about a system is returned to the controller of the system to improve its performance. An example of feedback and a feedback mechanism is the body's ability to control temperature. The condition of the body's temperature is the information fed back to the brain, which is the controller. If the temperature is high, the body sweats in order to cool down. Since the process of sweating is done to stop the temperature change, this is a negative feedback mechanism.
Another example is in psychology in a phenomenon known as "shame loops" that people who easily blush experience. When they realize that they are blushing, they become embarrassed about it, which then causes them to blush even more, creating a positive feedback mechanism. The positive and negative naming of the mechanisms do not indicate whether the feedback is good or bad.