A metropolitan municipality is a type of municipality established in some countries to serve a metropolitan area.
Metropolitan municipality Wikipedia
In generic terms, and in practical application within Canada, a metropolitan municipality is an urban local government; or at least a suburban government flanked by urban and/or other suburban counties. Conversely, a rural area (or a suburban area flanked mostly by rural areas) in which county and municipal functions are consolidated in one government is not a metropolitan municipality but a regional municipality.
The most typical distinction, in historical terms, is that a metropolitan municipality is usually a consolidation of one urban city and the county in which it is located. A regional municipality, by contrast, is usually a consolidation of two or more suburban and/or rural cities, towns or villages - each of which remains a geographically distinct area, usually because of greenspace between them - and the county in which they are located.Àrea Metropolitana de Barcelona
City State of Berlin
Metropolitan Association of Upper Silesia
Greater London Authority
Grande Área Metropolitana
Metropolitan municipalities of Italy