A core-based statistical area (CBSA) is a U.S. geographic area defined by the Office of Management and Budget (OMB). It contains a large population nucleus, or urban area, and adjacent communities that have a high degree of integration with that nucleus.
On July 15, 2015, the OMB released new standards based on the 2010 census. These standards are used to replace the definitions of metropolitan areas from the 2010 United States census data.
A metropolitan area or metro is a region consisting of a densely populated urban agglomeration and its surrounding territories which share industries, commercial areas, transport network, infrastructure and housing. A metropolitan area usually comprises multiple principal cities, jurisdictions and municipalities: neighborhoods, townships, boroughs, cities, towns, exurbs, suburbs, counties, districts and even states and nations in areas like the eurodistricts. As social, economic and political institutions have changed, metropolitan areas have become key economic and political regions.
In the United States, metropolitan areas are delineated around the core of a core based statistical area, which is defined as an urban area and includes central and outlying counties. In other countries metropolitan areas are sometimes anchored by one central city such as the Paris metropolitan area (Paris). In other cases, metropolitan areas contain multiple centers of equal or close to equal importance, especially in the United States; for example, the DallasâFort Worth metropolitan area has eight principal cities. The IslamabadâRawalpindi metropolitan area in Pakistan, the Rhine-Ruhr in Germany, and the Randstad in The Netherlands are other examples.