A city is a
human settlement of notable size.
[Goodall, B. (1987) ''The Penguin Dictionary of Human Geography''. London: Penguin.][Kuper, A. and Kuper, J., eds (1996) ''The Social Science Encyclopedia''. 2nd edition. London: Routledge.] It can be defined as a permanent and
densely settled place with administratively defined boundaries whose members work primarily on non-agricultural tasks. Cities generally have extensive systems for
housing,
transportation,
sanitation,
utilities,
land use,
production of goods, and
communication. Their density facilitates interaction between people,
government organisations and
businesses, sometimes benefiting different parties in the process, such as improving efficiency of goods and service distribution.
Historically, city-dwellers have been a small proportion of humanity overall, but following two centuries of unprecedented and rapid
urbanization, more than half of the
world population now lives in cities, which has had profound consequences for global sustainability. Present-day cities usually form the core of larger
metropolitan area
A metropolitan area or metro is a region that consists of a densely populated urban agglomeration and its surrounding territories sharing industries, commercial areas, transport network, infrastructures and housing. A metro area usually com ...
s and
urban areas—creating numerous
commuters traveling towards
city centre
A city centre is the commercial, cultural and often the historical, political, and geographic heart of a city. The term "city centre" is primarily used in British English, and closely equivalent terms exist in other languages, such as "" in Fren ...
s for employment, entertainment, and education. However, in a world of intensifying
globalization, all cities are to varying degrees also connected globally beyond these regions. This increased influence means that cities also have significant influences on global issues, such as
sustainable development
Sustainable development is an organizing principle for meeting human development goals while also sustaining the ability of natural systems to provide the natural resources and ecosystem services on which the economy and society depend. The des ...
,
global warming, and
global health. Because of these major influences on global issues, the international community has prioritized investment in
sustainable cities
The sustainable city, eco-city, or green city is a city designed with consideration for social, economic, environmental impact (commonly referred to as the triple bottom line), and resilient habitat for existing populations, without compromisi ...
through
Sustainable Development Goal 11
Sustainable Development Goal 11 (SDG 11 or Global Goal 11), titled " sustainable cities and communities", is one of 17 Sustainable Development Goals established by the United Nations General Assembly in 2015. The official mission of SDG 11 is ...
. Due to the efficiency of transportation and the smaller
land consumption,
dense cities hold the potential to have a smaller
ecological footprint
The ecological footprint is a method promoted by the Global Footprint Network to measure human demand on natural capital, i.e. the quantity of nature it takes to support people or an economy. It tracks this demand through an ecological accounti ...
per inhabitant than more sparsely populated areas. Therefore,
compact cities are often referred to as a crucial element of fighting climate change. However, this concentration can also have significant negative consequences, such as forming
urban heat islands,
concentrating pollution, and stressing water supplies and other resources.
Other important traits of cities besides population include the capital status and relative continued occupation of the city. For example, country capitals such as
Beijing,
London,
Mexico City,
Moscow,
Nairobi,
New Delhi,
Paris,
Rome,
Athens,
Seoul,
Singapore,
Tokyo,
Manila, and
Washington, D.C. reflect the identity and apex of their respective nations. Some historic capitals, such as
Kyoto and
Xi'an, maintain their reflection of cultural identity even without modern capital status. Religious holy sites offer another example of capital status within a religion,
Jerusalem,
Mecca,
Varanasi,
Ayodhya,
Haridwar and
Prayagraj each hold significance.
Meaning
A city can be distinguished from other human settlements by its relatively great size, but also by its functions and its
special symbolic status, which may be conferred by a central authority. The term can also refer either to the physical streets and buildings of the city or to the collection of people who dwell there, and can be used in a general sense to mean
urban rather than
rural territory
Selsoviet ( be, сельсавет, r=sieĺsaviet, tr. ''sieĺsaviet''; rus, сельсовет, p=ˈsʲelʲsɐˈvʲɛt, r=selsovet; uk, сільрада, silrada) is a shortened name for a rural council and for the area governed by such a cou ...
.
[Kevin A. Lynch, "What Is the Form of a City, and How is It Made?"; in Marzluff et al. (2008), p. 678. "The city may be looked on as a story, a pattern of relations between human groups, a production and distribution space, a field of physical force, a set of linked decisions, or an arena of conflict. Values are embedded in these metaphors: historic continuity, stable equilibrium, productive efficiency, capable decision and management, maximum interaction, or the progress of political struggle. Certain actors become the decisive elements of transformation in each view: political leaders, families and ethnic groups, major investors, the technicians of transport, the decision elite, the revolutionary classes."]
National
censuses use a variety of definitions – invoking factors such as
population,
population density, number of
dwelling
In law, a dwelling (also known as a residence or an abode) is a self-contained unit of accommodation used by one or more households as a home - such as a house, apartment, mobile home, houseboat, vehicle, or other "substantial" structure. The ...
s, economic function, and
infrastructure
Infrastructure is the set of facilities and systems that serve a country, city, or other area, and encompasses the services and facilities necessary for its economy, households and firms to function. Infrastructure is composed of public and priv ...
– to classify populations as urban. Typical working definitions for small-city populations start at around 100,000 people. Common population definitions for an urban area (city or town) range between 1,500 and 50,000 people, with most
U.S. states using a minimum between 1,500 and 5,000 inhabitants.
Some jurisdictions set no such minima. In the
United Kingdom,
city status is awarded by the Crown and then remains permanently. (Historically, the qualifying factor was the presence of a
cathedral, resulting in some very small cities such as
Wells
Wells most commonly refers to:
* Wells, Somerset, a cathedral city in Somerset, England
* Well, an excavation or structure created in the ground
* Wells (name)
Wells may also refer to:
Places Canada
*Wells, British Columbia
England
* Wells ...
, with a population 12,000 and
St Davids
St Davids or St David's ( cy, Tyddewi, , "David's house”) is a city and a community (named St Davids and the Cathedral Close) with a cathedral in Pembrokeshire, Wales, lying on the River Alun. It is the resting place of Saint David, W ...
, with a population of 1,841 .) 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 serve as administrative, commercial, religious, and cultural hubs for their larger surrounding areas.
[Marshall (1989), pp. 14–15.]
The presence of a
literate elite is sometimes included in the definition. A typical city has professional
administrators, regulations, and some form of
taxation (food and other necessities or means to trade for them) to support the
government workers. (This arrangement contrasts with the more typically
horizontal
Horizontal may refer to:
*Horizontal plane, in astronomy, geography, geometry and other sciences and contexts
*Horizontal coordinate system, in astronomy
*Horizontalism, in monetary circuit theory
*Horizontalism, in sociology
*Horizontal market, ...
relationships in a
tribe or
village accomplishing common goals through informal agreements between neighbors, or through
leadership of a chief.) The governments may be based on heredity, religion, military power, work systems such as canal-building, food-distribution, land-ownership, agriculture, commerce, manufacturing, finance, or a combination of these. Societies that live in cities are often called
civilizations.
The ''degree of urbanization'' is a modern metric to help define what comprises a city: "a population of at least 50,000 inhabitants in contiguous dense grid cells (>1,500 inhabitants per square kilometer)". This metric was "devised over years by the
European Commission,
OECD,
World Bank and others, and endorsed in March
021
021 is:
* in Brazil, the telephone area code for the city of Rio de Janeiro and surrounding cities (Greater Rio de Janeiro)
* in China, the telephone area code for the city of Shanghai.
* in Indonesia, the area code for the city of Jakarta and su ...
by the
United Nations... largely for the purpose of international statistical comparison".
Etymology
The word ''city'' and the related ''
civilization'' come from the
Latin root ''
civitas
In Ancient Rome, the Latin term (; plural ), according to Cicero in the time of the late Roman Republic, was the social body of the , or citizens, united by law (). It is the law that binds them together, giving them responsibilities () on th ...
'', originally meaning 'citizenship' or 'community member' and eventually coming to correspond with ''
urbs'', meaning 'city' in a more physical sense.
["city, n.", ''Oxford English Dictionary'', June 2014.] The Roman ''civitas'' was closely linked with the Greek ''
polis''—another common root appearing in English words such as ''
metropolis''.
In
toponymic terminology, names of individual cities and towns are called ''astionyms'' (from
Ancient Greek ἄστυ 'city or town' and ὄνομα 'name').
Geography
Urban geography deals both with cities in their larger context and with their internal structure. Cities are estimated to cover about 3% of the land surface of the Earth.
Site
Town siting has varied through history according to natural, technological, economic, and military contexts. Access to water has long been a major factor in city placement and growth, and despite exceptions enabled by the advent of
rail transport in the nineteenth century, through the present most of the world's urban population lives near the coast or on a river.
Urban areas as a rule cannot
produce their own food and therefore must develop some
relationship
Relationship most often refers to:
* Family relations and relatives: consanguinity
* Interpersonal relationship, a strong, deep, or close association or acquaintance between two or more people
* Correlation and dependence, relationships in mathem ...
with a
hinterland which sustains them.
[Kaplan et al. (2004), pp. 155–156.] Only in special cases such as
mining town
A mining community, also known as a mining town or a mining camp, is a community that houses miners. Mining communities are usually created around a mine or a quarry.
Historic mining communities
Australia
* Ballarat, Victoria
* Bendigo, ...
s which play a vital role in long-distance trade, are cities disconnected from the countryside which feeds them.
[Marshall (1989), p. 15. "The mutual interdependence of town and country has one consequence so obvious that it is easily overlooked: at the global scale, cities are generally confined to areas capable of supporting a permanent agricultural population. Moreover, within any area possessing a broadly uniform level of agricultural productivity, there is a rough but definite association between the density of the rural population and the average spacing of cities above any chosen minimum size."] Thus, centrality within a productive region influences siting, as economic forces would in theory favor the creation of market places in optimal mutually reachable locations.
Center
The vast majority of cities have a central area containing buildings with special economic, political, and religious significance. Archaeologists refer to this area by the Greek term
temenos or if fortified as a
citadel. These spaces historically reflect and amplify the city's centrality and importance to its wider
sphere of influence.
[Latham et al. (2009), p. 18. "From the simplest forms of exchange, when peasant farmers literally brought their produce from the fields into the densest point of interaction—giving us market towns—the significance of central places to surrounding territories began to be asserted. As cities grew in complexity, the major civic institutions, from seats of government to religious buildings, would also come to dominate these points of convergence. Large central squares or open spaces reflected the importance of collective gatherings in city life, such as Tiananmen Square in Beijing, the Zócalo in Mexico City, the Piazza Navonae in Rome and Trafalgar Square in London.] Today cities have a
city center or
downtown
''Downtown'' is a term primarily used in North America by English speakers to refer to a city's sometimes commercial, cultural and often the historical, political and geographic heart. It is often synonymous with its central business distric ...
, sometimes coincident with a
central business district
A central business district (CBD) is the commercial and business centre of a city. It contains commercial space and offices, and in larger cities will often be described as a financial district. Geographically, it often coincides with the "city ...
.
Public space
Cities typically have
public spaces where anyone can go. These include
privately owned spaces open to the public as well as forms of public land such as
public domain and the
commons.
Western philosophy since the time of the Greek
agora
The agora (; grc, ἀγορά, romanized: ', meaning "market" in Modern Greek) was a central public space in ancient Greek city-states. It is the best representation of a city-state's response to accommodate the social and political order of t ...
has considered physical public space as the substrate of the symbolic
public sphere.
Public art adorns (or disfigures) public spaces.
Park
A park is an area of natural, semi-natural or planted space set aside for human enjoyment and recreation or for the protection of wildlife or natural habitats. Urban parks are urban green space, green spaces set aside for recreation inside t ...
s and other
natural sites within cities provide residents with relief from the hardness and regularity of typical
built environments.
Internal structure
Urban structure generally follows one or more basic patterns: geomorphic, radial, concentric, rectilinear, and curvilinear. Physical environment generally constrains the form in which a city is built. If located on a mountainside, urban structure may rely on terraces and winding roads. It may be adapted to its means of subsistence (e.g. agriculture or fishing). And it may be set up for optimal defense given the surrounding landscape. Beyond these "geomorphic" features, cities can develop internal patterns, due to natural growth or to
city planning.
In a radial structure, main roads converge on a central point. This form could evolve from successive growth over a long time, with concentric traces of
town walls and
citadels marking older city boundaries. In more recent history, such forms were supplemented by
ring road
A ring road (also known as circular road, beltline, beltway, circumferential (high)way, loop, bypass or orbital) is a road or a series of connected roads encircling a town, city, or country. The most common purpose of a ring road is to assist i ...
s moving traffic around the outskirts of a town. Dutch cities such as
Amsterdam and
Haarlem
Haarlem (; predecessor of ''Harlem'' in English) is a city and municipality in the Netherlands. It is the capital of the province of North Holland. Haarlem is situated at the northern edge of the Randstad, one of the most populated metropoli ...
are structured as a central square surrounded by concentric canals marking every expansion. In cities such as
Moscow, this pattern is still clearly visible.
A system of rectilinear city streets and land plots, known as the
grid plan
In urban planning, the grid plan, grid street plan, or gridiron plan is a type of city plan in which streets run at right angles to each other, forming a grid.
Two inherent characteristics of the grid plan, frequent intersections and orthogona ...
, has been used for millennia in Asia, Europe, and the Americas. The
Indus Valley civilisation built
Mohenjo-Daro,
Harappa
Harappa (; Urdu/ pnb, ) is an archaeological site in Punjab, Pakistan, about west of Sahiwal. The Bronze Age Harappan civilisation, now more often called the Indus Valley Civilisation, is named after the site, which takes its name from a mode ...
and other cities on a grid pattern, using ancient principles described by
Kautilya, and aligned with the
compass points.
[Smith,]
Earliest Cities
", in Gmelch & Zenner (2002). The ancient Greek city of
Priene exemplifies a grid plan with specialized districts used across the
Hellenistic Mediterranean.
Urban areas
Urban-type settlement extends far beyond the traditional boundaries of the
city proper in a form of development sometimes described critically as
urban sprawl. 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
A suburb (more broadly suburban area) is an area within a metropolitan area, which may include commercial and mixed-use, that is primarily a residential area. A suburb can exist either as part of a larger city/urban area or as a separate ...
and
exurbs
An exurb (or alternately: exurban area) is an area outside the typically denser inner suburban area, at the edge of a metropolitan area, which has some economic and commuting connection to the metro area, low housing density, and growth. It sh ...
organized around the needs of
commuters, and sometimes
edge cities
''Edge city'' is a term that originated in the United States for a concentration of business, shopping, and entertainment outside a traditional downtown or central business district, in what had previously been a suburban residential or ru ...
characterized by a degree of economic and political independence. (In the US these are grouped into
metropolitan statistical areas for purposes of
demography and
marketing.) Some cities are now part of a continuous urban landscape called
urban agglomeration,
conurbation
A conurbation is a region comprising a number of metropolises, cities, large towns, and other urban areas which through population growth and physical expansion, have merged to form one continuous urban or industrially developed area. In most ca ...
, or
megalopolis