Homeostasis (from Greek: ὅμοιος, hómoios, "similar", and στάσις, stásis, "standing still") is the property of a system that regulates its internal environment and tends to maintain a stable, relatively constant condition of properties such as temperature or pH. It can be either an open or closed system. In simple terms, it is basically a process in which the body's internal environment is kept stable.
It was defined by Claude Bernard and later by Walter Bradford Cannon in 1926, 1929 and 1932.
Typically used to refer to a living organism, the concept came from that of milieu intérieur that was created by Claude Bernard and published in 1865. Multiple dynamic equilibrium adjustment and regulation mechanisms make homeostasis possible.
Read more about Homeostasis: Biological, Ecological, Biosphere, Reactive, Psychological