Some cities of a country have special importance over others. Some are capitals and some are important trading centers . These are called metropolitan cities.
A metropolitan area, sometimes referred to as a metro area or commuter belt, is a region consisting of a densely populated urban core and its less-populated surrounding territories, sharing industry, infrastructure, and housing.[1] A metro area usually comprises multiple jurisdictions and municipalities: neighborhoods, townships, boroughs, cities, towns, exurbs, suburbs, counties, districts, states, and even nations like the eurodistricts. As social, economic and political institutions have changed, metropolitan areas have become key economic and political regions.[2] Metropolitan areas include one or more urban areas, as well as satellite cities, towns and intervening rural areas that are socioeconomically tied to the urban core, typically measured by commuting patterns.[3] In the United States, the concept of the metropolitan statistical area has gained prominence.
For urban centres outside metropolitan areas, that generate a similar attraction at smaller scale for their region, the concept of the regiopolis and respectively regiopolitan area or regio was introduced by German professors in 2006.[4] In the United States, the term micropolitan statistical area is used.
General definition
A metropolitan area combines an urban agglomeration (the contiguous, built-up area) with zones not necessarily urban in character, but closely bound to the center by employment or other commerce. These outlying zones are sometimes known as a commuter belt, and may extend well beyond the urban zone, to other political entities. For example, Islip, New York on Long Island is considered part of the New York metropolitan area.
In practice, the parameters of metropolitan areas, in both official and unofficial usage, are not consistent. Sometimes they are little different from an urban area, and in other cases they cover broad regions that have little relation to a single urban settlement; comparative statistics for metropolitan area should take this into account. Population figures given for one metro area can vary by millions.
There has been no significant change in the basic concept of metropolitan areas since its adoption in 1950,[5] although significant changes in geographic distributions have occurred since then, and more are expected.[6] Because of the fluidity of the term "metropolitan statistical area," the term used colloquially is more often "metro service area," "metro area," or "MSA" taken to include not only a city, but also surrounding suburban, exurban and sometimes rural areas, all which it is presumed to influence. A polycentric metropolitan area contains multiple urban agglomerations not connected by continuous development. In defining a metropolitan area, it is sufficient that a city or cities form a nucleus with which other areas have a high degree of integration.
See also the many lists of metropolitan areas itemized at § Lists of metropolitan areas.