Region is most commonly a term used in terrestrial sciences and astrophysics. Among the different sub-disciplines of geography it is an area studied by regional geographers. Regions consist of subregions that contain clusters of like areas that are distinctive by their uniformity of description based on a range of statistical data, for example demographic, and locales. In astrophysics some regions have science-specific terms such as galactic clusters.
In Geography, regions can be broadly divided by physical characteristics (physical geography), human impact characteristics (human geography), and the interaction of Humanity and the environment (environmental geography). Geographic regions and subregions are mostly described by their imprecisely defined, and sometimes transitory boundaries, except in human geography where jurisdiction areas such as national borders are clearly defined in law.
Apart from the global continental regions, there are also hydrospheric and atmospheric regions that cover the oceans, and discrete climates above the land and water masses of the planet. The land and water global regions are divided into subregions geographically bounded by large geological features that influence large-scale ecologies, such as plains and steppes, forested massifs, deserts, or mountainous regions. Subregions describe the areas within regions that are easily distinguished in both the geological and ecological observable features.