Conversation so far:
what is meant by a negative feedback system
Negative feedback occurs when some function of the output of a system, process, or mechanism is fed back in a manner that tends to reduce the fluctuations in the output.
how is the negative system different from positive feedback
The positive feedback tends to lead to instability via exponential growth, oscillation or chaotic behavior, negative system feedback generally promotes stability.

Question: how is the system important to life
Self-contained rewrite: how are negative feedback systems important to real life