From The Art and Popular Culture Encyclopedia
"OUR earth is but as an atom in space, a star amongst stars. Yet, to us who inhabit it, it is still without bounds, as it was in the time of our barbarian ancestors. Nor can we foresee the period when the whole of its surface will be known to us. We have been taught by astronomers and geodesists that our planet is a sphere flattened at the poles, and physical geographers and meteorologists have applied their powers of inductive reasoning to establish theories on the direction of the winds and ocean currents within the polar regions. But hitherto no explorer has succeeded in reaching the extremities of our earth, and no one can tell whether land or sea extends beyond those icy barriers which have frustrated our most determined efforts. Thanks to the struggles of indomitable seamen, the pride of our race, the area of the mysterious regions around the north pole has been reduced to something like the hundredth part of the earth’s surface, but in the south there still remains an unknown region of such vast extent, that the moon, were she to drop upon our planet, might disappear within it without coming into contact with any part of the earth’s surface already known to us."--The Earth and Its Inhabitants (1875–1894) by Élisée Reclus
In geography, regions are areas 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 sub regions 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 features.
As a way of describing spatial areas, the concept of regions is important and widely used among the many branches of geography, each of which can describe areas in regional terms. For example, ecoregion is a term used in environmental geography, cultural region in cultural geography, bioregion in biogeography, and so on. The field of geography that studies regions themselves is called regional geography.
In the fields of physical geography, ecology, biogeography, zoogeography, and environmental geography, regions tend to be based on natural features such as ecosystems or biotopes, biomes, drainage basins, natural regions, mountain ranges, soil types. Where human geography is concerned, the regions and subregions are described by the discipline of ethnography.
A region has its own nature that could not be moved. The first nature is its natural environment (landform, climate, etc.). The second nature is its physical elements complex that were built by people in the past. The third nature is its socio-cultural context that could not be replaced by new immigrants.