"Homeostasis is the property of a system within an organism in which a variable, such as the concentration of a substance in solution, is actively regulated to remain very nearly constant. Examples of homeostasis include the regulation of body temperature, the pH of extracellular fluid, or the concentrations of sodium, potassium and calcium ions, as well as that of glucose in the blood plasma, despite changes in the environment, diet, or level of activity. Each of these variables is controlled by a separate regulator or homeostatic mechanism, which, together, maintain life. The concept was described by French physiologist Claude Bernard in 1865 and the word was coined by Walter Bradford Cannon in 1926." - Wikipedia
James Clear Mental Models Overview