Geographic areas area then defined as being urban or rural. The complete definition of urban is long and involved, but basically any settled area of 2,500 or more is considered to be urban.
Rural areas are the remainder.
A change in requirements between 1970 and 1980 added between 200 and 300 urban areas. Because rural is anything that is not urban, rural does not necessarily imply a farm or county side. Rural includes small places and sparcely populated areas. Urban and Rural definitions are independent of metropolitan area definitions. Urban and rural can occur inside of and outside of metropolitan areas.