Population

 Population population , in   human   biology , the whole number of inhabitants occupying an area (such as a   country   or the world) and continually being modified by increases (births and   immigrations ) and losses ( deaths   and emigrations). As with any biological population, the size of a human population is limited by the supply of food, the effect of   diseases , and other environmental factors. Human populations are further affected by social customs governing reproduction and by the technological developments, especially in   medicine   and   public health , that have reduced   mortality   and extended the life span. Few aspects of human societies are as fundamental as the size,  composition , and rate of change of their populations. Such factors affect economic prosperity,  health , education, family structure, crime patterns, language, culture—indeed, virtually every aspect of human society is touche...