thumb|Exurban-style density along the [[Delaware–Maryland–Pennsylvania Tri-State Point|Delaware–Maryland–Pennsylvania border, part of the Philadelphia metropolitan area]]
thumb|Exurban development (left side) blends into suburban development (right side) in [[Loudoun County, Virginia, in the western part of the Baltimore–Washington metropolitan area.]]
An exurb (sometimes exurban area), sometimes called and/or associated with a semi-rural area or subrural area, is an urbanized area outside the typically denser inner suburban areas of a city, located at the edge of a metropolitan area. It has some of the same economic and commuting connection to the metro area as a typical suburb, but with considerably lower commercial density
and relatively high population growth.
It shapes an interface between urban and rural landscapes, holding a limited urban nature for its functional, economic, and social interaction with the urban center, due to its dominant residential character. Exurbs consist of "agglomerations of housing and jobs outside the municipal boundaries of a primary city" and beyond the surrounding suburbs.