Quality of Human life depends on the physical and psychological health or welfare of an individual or a society. Health and welfare in turn, depend on the degree to which a person's or a society's respective environments satisfy their needs; needs vary substantially by culture, age, sex, season, climate, education and income. Some must be satisfied before others are felt. It is often difficult to distinguish between "needs" and "wants" and lack of information and understanding often undo efforts to improve one's quality of life. If the allotment of resources required satisfying any of their perceived needs is not sufficient or, though sufficient is placed in jeopardy, that society will believe that its quality of life is threatened and will fight to save or restore it. Each environment is a system, which overlaps, influences, and is influenced by other systems. They resemble ecosystems (or are at least significant parts of ecosystems) in that they are units of space where biotic and physical components and processes interact to develop patterns of energy and material flow and cycling.
