Ecology, or ecological science, is the scientific study of the distribution and abundance of living organisms and how the distribution and abundance are affected by interactions between the organisms and their environment. The environment of an organism includes both physical properties, which can be described as the sum of local abiotic factors such as solar insolation, climate and geology, as well as the other organisms that share its habitat. The term Ökologie was coined in 1866 by the German biologist Ernst Haeckel; the word is derived from the Greek οικος (oikos, "household") and λόγος (logos, "study"); therefore "ecology" means the "study of the household (of nature)".
Ecology is also a human science. There are many practical applications of ecology in conservation biology, wetland management, natural resource management (agriculture, forestry, fisheries), city planning (urban ecology), community health, economics, basic and applied science and human social interaction (human ecology).