Answer
The main difference between a negative and positive feedback system is that one tries to strengthen a change occurring in the body in order to reach a certain outcome by releasing necessary responses (positive feedback system), while the other works against a change in the body in order to achieve homeostasis and regulation while also stimulating certain responses (negative feedback system).
Work Step by Step
For example:
The positive feedback system works to increase/ strengthen a certain change or stimulus in the body. A positive feedback system is present during childbirth and that's mainly because it works to enhance the bodily changes occurring during childhood such as the contractions that occur as the baby pushes its way through the cervix, through the uterus, etc. During this process, the positive feedback system sends impulses to the brain which release a hormone that enhances contractions, increasing them significantly, thus encouraging the stimulus that is occurring in order to achieve childbirth. Once the baby is born, the process automatically stops because the job of the positive feedback comes to an end when the contractions stop and the cervix is relaxed.
Since a negative feedback system works to maintain homeostasis and regulate bodily conditions, it works to stop a change in the body by returning the body to a maintained ("normal") state. An example of a negative feedback system would simply be when anything goes out of the homeostasis range of the body or its "normal" state. A good example would be the rise of the body's temperature. When one becomes sick, and the body temperature rises, the negative feedback system stimulates the sweat glands and sweating occurs in order to decrease the temperature by cooling the body. On the other hand, in cold conditions, if the body temperature goes below normal, the negative feedback system while trigger shivering in order to increase the body temperature.
