Peter Senge, in The Fifth Discipline defines two types of feedback. Reinforcing and Balancing Feedback.
These two forms of feedback are typically expressed in terms of a loop, the feedback is invested back into the system forming Circles of Causality.
This is the basic idea of Systems Thinking, that every action triggers reactions, that trigger further actions. Forming a circle of causality.
Reinforcing Feedback is that which accelerates change in a system towards a positive or negative trend. Positively Reinforcing Feedback is what is typically desired, some examples might be viral videos, or in Agile development if done well the regular practice (action) of retrospectives and stand-ups can have a positively trending effect through process improvement (reactions). These practices are a good example because these actions when poorly done can also have a negative trend.
Balancing Feedback is that which maintains the system in a stable state. This can be a good or bad thing - depending if there is a desired change to be done to the system. An example might be a failed change program in an organisation - a change program typically fails because there is a strong balancing feedback loop present in the system that is auto correcting itself to maintain the current state. This may be due to the attitudes and goals of the system and a failure for the change program to target the correct causes.