Regulators : Some organisms are able to maintain homeostasis by physiological and behavioral means which ensures constant body temperature, constant osmotic concentration etc. All birds and mammals and a very few lower vertebrate and invertebrate species are capable of such regulation. The success of mammals is lagely due to their ability to maintain a constant body temperature and thrive whether they live Antarctica or in the Sahara desert.
Conformers : The body temperature of animals and plants changes with the surrounding temperature. In aquatic animals, the osmotic concentration of the body fluids changes with that of surrounding water osmotic concentration. These animals and plants are simply conformers. This is because, these organisms can regulate only over a limited range of environmental conditions beyond which they only conform.