In other words, the term homeostasis is being used to describe the body’s maintenance during resting conditions whereas the term steady state refers to the body’s maintenance during exercise; exercise is a stressor which disrupts homeostasis, also called homeostatic disturbance (e.g. an increase in temperature).
Homeostasis is the maintenance of a constant internal environment (the immediate surroundings of cells) in response to changes in:
the changing conditions of the external environment.
the changing conditions of the internal environment.
Homeostasis is a self adjusting mechanism involving feedback where the response to a stimulus alters the internal conditions and may itself become a new stimulus.
Homeostasis works to maintain the organism's internal environment within tolerance limits - the narrow range of conditions where cellular processes are able to function at a level consistent with the continuation of life.