A Combined Statistical Area (CSA) is defined by the U.S. Census Bureau as a combination of several adjacent Metropolitan Statistical Areas (MSAs) or Micropolitan Statistical Areas (μSAs), or a mix of the two, which are linked by economic ties.
A metropolitan area is generally a developed region that is economically attached to a large central city, encompassing towns, suburbs, and other peripheral areas.
A Metropolitan Division is a county or group of counties within a large Metropolitan Statistical Area (MSA) that functions as a distinct economic area.
A Metropolitan Statistical Area (MSA) is a Core-Based Statistical Area associated with at least one urbanized area with a population of at least 50,000. An MSA comprises the central county or counties containing the core, plus adjacent outlying counties with a high degree of social and economic integration with the central county as measured through commuting.
