A negative feedback mechanism is a series of reactions or processes that mitigate a change or disturbance within a system. This type of feedback mechanism has the tendency to return the system to an equilibrium state.
A feedback corresponds to variations in a particular variable. Feedback mechanisms, also referred to as loops, are often cyclical, wherein a system undergoes repetitive steps. A feedback mechanism can either be positive or negative. When the change that occurs within the system is augmented or amplified, the feedback mechanism is said to be positive.
A negative feedback mechanism, meanwhile, reduces the impact of an initial change to make the system more stable or with minimal variations. In terms of geological systems, the formation of clouds and weathering of rocks are examples of negative feedback mechanisms.