Cities serve as administrative, commercial, religious, and cultural hubs for their larger surrounding areas.
A typical city has professional administrators, regulations, and some form of taxation (food and other necessities or means to trade for them) to feed the government workers.
Urban-type settlement extends far beyond the traditional boundaries of the city proper Decentralization and dispersal of city functions (commercial, industrial, residential, cultural, political) has transformed the very meaning of the term and has challenged geographers seeking to classify territories according to an urban-rural binary.
Metropolitan areas include suburbs and exurbs organized around the needs of commuters, and sometimes edge cities characterized by a degree of economic and political independence.
In others, such as in the United Kingdom, city status is awarded on local criteria.
According to the "functional definition" a city is not distinguished by size alone, but also by the role it plays within a larger political context.
Cities generally have extensive systems for housing, transportation, sanitation, utilities, land use, and communication.
Societies that live in cities are often called civilizations.
Western philosophy since the time of the Greek agora has considered physical public space as the substrate of the symbolic public sphere. Parks and other natural sites within cities provide residents with relief from the hardness and regularity of typical built environments.
Urban structure generally follows one or more basic patterns: geomorphic, radial, concentric, rectilinear, and curvilinear.
The Indus Valley Civilisation built Mohenjo-Daro, Harappa and other cities on a grid pattern, using ancient principles described by Kautilya, and aligned with the compass points.
The ancient Greek city of Priene exemplifies a grid plan with specialized districts used across the Hellenistic Mediterranean.