Hi there, i'll do the best I can I hope this answers your question.
Positive vs. Negative Feedback. The key difference between positive and negative feedback is their response to change: positive feedback amplifies change while negative feedback reduces change. This means that positive feedback will result in more of a product: more apples, more contractions, or more clotting platelets ...
positive feedback amplifies a change ... can lead to oscillations system instability and saturation
if a loudspeaker is close to a microphone a very loud squeal = + fb
lasers may use same idea
