City

A city is a place where many people live close together. The word means different things in different parts of the world, and in some places a settlement can be quite small. There is no agreed number that marks the smallest size a place must be to count as a city. In a more specific sense, a city is a permanent, densely populated place with set boundaries, where most people work at jobs that are not farming.

Cities usually have large systems for housing, transportation, sanitation, utilities, land use, production of goods, and communication. Living close together makes it easier for people, government organizations, and businesses to interact. This can help different groups, such as by making the delivery of goods and services more efficient. Cities around the world include Lagos, one of the fastest-growing megacities, Tokyo, Paris, Rio de Janeiro, Manhattan, Delhi, Hong Kong, and São Paulo.

Historically, city dwellers were a small part of humanity overall. After two centuries of fast and unprecedented urbanization, more than half of the world population now lives in cities. This has had deep effects on global sustainability. Today's cities usually form the centre of larger metropolitan areas and urban areas, and many commuters travel toward city centres for work, entertainment, and education. As the world becomes more connected through globalization, all cities are linked to the wider world to some degree. Cities therefore have a big influence on global issues such as sustainable development, climate change, and global health.

Because of these effects, the international community has made investing in sustainable cities a priority through Sustainable Development Goal 11. Dense cities use less land and transportation is more efficient, so they can have a smaller ecological footprint per person than more spread-out areas. For this reason, compact cities are often described as an important way to fight climate change. However, this concentration of people can also cause harmful effects, such as urban heat islands, concentrated pollution, and strain on water supplies and other resources.

Other meanings of the word are explained on City (disambiguation).

Meaning

Common population minimums for an urban area, which can be a city or a town, range from 1,500 to 50,000 people. Most U.S. states use a minimum between 1,500 and 5,000 inhabitants, and some places set no such rules. National censuses use factors such as population density, the number of dwellings, economic role, and infrastructure to decide which populations are urban.

A city is set apart by its large size, its functions, and its special symbolic status. The word can refer to the streets and buildings or to the people who live there, and it can mean urban rather than rural territory. Under the "functional definition," a city is also defined by its role in a larger political context, serving as a hub for administration, trade, religion, and culture in the area around it. Cities usually have professional administrators, rules, and some form of taxation to support government workers. This differs from the more horizontal ways a tribe or village works through informal agreements between neighbors, or under the leadership of a chief. Societies that live in cities are often called civilizations. The degree of urbanization, a modern measure devised by the European Commission, OECD, World Bank and others, counts a city as at least 50,000 inhabitants in dense areas, and it was endorsed in March 2021 by the United Nations. Typical working definitions for small-city populations start at around 100,000 people. In Australia, what counts as a city varies between the states. In the United Kingdom, city status was once limited to settlements with diocesan cathedrals, but it is now awarded by the Crown and stays permanent, with two exceptions. This older rule leads to some very small cities, such as St Davids, with a population of 1,751 as of 2021.

Etymology

The word city comes from the Old French word cité, which came from the Latin word civitas, meaning "citizenship" or "state". The related word civilization may also come from the Latin root civitas. This word first meant "citizenship" or "community member," and later it came to mean "city" in a more physical sense. The Roman civitas was closely linked with the Greek polis, which appears in English words such as metropolis.

In toponymic terminology, the names of individual cities and towns are called astionyms. This word comes from Ancient Greek words meaning "city or town" (ἄστυ) and "name" (ὄνομα).

Geography

Urban geography looks at cities both in their wider setting and in their inner layout. Cities are estimated to cover about 3% of the land surface of the Earth. Towns have been placed in different spots over time depending on nature, technology, the economy, and the military. Access to water has long been a major factor, and although rail transport in the 1800s allowed some exceptions, most of the world's urban population today lives near the coast or on a river. Cities usually cannot produce their own food, so they need some relationship with a hinterland that supports them. Only special cases, such as mining towns that play a vital role in long-distance trade, are cut off from the countryside that feeds them.

Most cities have a central area with buildings of special economic, political, and religious importance. Archaeologists call this area by the Greek term temenos, or a citadel if it is fortified, and these spaces show the city's importance to its wider sphere of influence. Today, cities have a city center or downtown, sometimes overlapping with a central business district. Cities also have public spaces where anyone can go, including privately owned spaces open to the public, public domain, and the commons. Western philosophy since the time of the Greek agora has seen physical public space as the base of the symbolic public sphere. Public art decorates (or disfigures) these spaces, while Parks and natural sites within cities give residents relief from the hardness and regularity of built environments. Urban green spaces also help reduce the urban heat island effect, especially in warmer climates. The urban structure often follows one or more basic patterns: geomorphic, radial, concentric, rectilinear, and curvilinear. The land generally shapes how a city is built, and cities can also develop patterns through city planning. In radial cities, main roads meet at a central point, and old town walls and citadels can mark earlier boundaries, later supplemented by ring roads. Dutch cities such as Amsterdam and Haarlem have a central square surrounded by concentric canals, and Moscow still shows a similar pattern clearly. The grid plan of straight streets has been used for millennia. The Indus Valley Civilization built Mohenjo-Daro and Harappa on a grid, using principles described by Kautilya and aligned with the compass points, and the ancient Greek city of Priene shows a grid plan with specialized districts across the Hellenistic Mediterranean. Urban-type settlements extend well beyond the city proper, a pattern sometimes called urban sprawl. Metropolitan areas include suburbs and exurbs built around commuters, and sometimes edge cities with some economic and political independence. In the US they are grouped into metropolitan statistical areas for demography and marketing. Some cities form a continuous landscape called an urban agglomeration, conurbation, or megalopolis, such as the BosWash corridor of the Northeastern United States.

History

Main article: History of cities

Further information: Urban history, Historical urban community sizes, and List of largest cities throughout history

Cities have existed for thousands of years. Their development from proto-urban settlements, such as Çatalhöyük, was not a straight line. Some places, including Jericho, Aleppo, Byblos, Damascus, and Athens, claim to have been lived in continuously for the longest time. Most archaeologists consider the Mesopotamian city of Uruk, from the mid-fourth millennium BC, to be the first true city. Early cities often had granaries, and many were built where people could farm and trade. In the ancient world, great civilizations grew along river valleys, such as Mohenjo-daro in the Indus Valley. Rome was the first city to pass one million inhabitants. Cities also grew in the Andes, Mesoamerica, and West Africa, and some, such as Mexico City, are still inhabited today.

In the Middle Ages, the Khmer capital of Angkor became one of the largest preindustrial settlements in the world, and cities such as Timbuktu grew rich through trade. Cities in Europe, such as those of the Hanseatic League, joined together for defense and trade. Later, the growth of industry led to massive urbanization as people moved from rural areas into cities, bringing problems such as overcrowding and poor sanitation. In the late 20th century, some industrial cities, such as Detroit, began to shrink. Today, advances in High technology have helped some cities become centres of the knowledge economy, and some companies have proposed building new, Master-planned cities.

Main article: Urbanization

Urbanization is the process of people moving from rural areas to cities, driven by political, economic, and cultural factors. Until the 1700s, there was a balance between farming communities and towns with markets and small workshops. With the agricultural and industrial revolutions, the city population grew rapidly, through both migration and demographic expansion. In England, the share of people living in cities rose from 17% in 1801 to 72% in 1891. In 1900, 15% of the world's population lived in cities. Cities also attract people because of their culture. Urbanization spread quickly across Europe and the Americas, and since the 1950s it has also taken hold in Asia and Africa. In 2014, the United Nations Department of Economic and Social Affairs reported that for the first time, more than half of the world's people live in cities. Latin America is the most urban continent, with four-fifths of its people living in cities, and about one-fifth living in shantytowns (favelas, poblaciones callampas, and similar areas). Batam, Indonesia, Mogadishu, Somalia, Xiamen, China, and Niamey, Niger, are among the fastest-growing cities, with yearly growth of 5–8%. Cities in the more developed countries of the "Global North" are still more urbanized than those in the less developed countries of the "Global South," but the gap is getting smaller because urbanization is happening faster in the Global South. Asia has by far the largest number of city dwellers, over two billion. The UN predicts 2.5 billion more city dwellers worldwide by 2050, with 90% of the growth happening in Asia and Africa. Megacities, cities with millions of people, have grown into the dozens, especially in Asia, Africa, and Latin America. Global economic ties fuel their growth as foreign capital pays for fast industrial growth, as major businesses move from Europe and North America via the relocation of major businesses, and as immigrants arrive from near and far. These cities often have a very wealthy elite living in gated communities and large numbers of people living in poor housing with weak infrastructure. Cities have also grown outward, with more land covered, more high-rise buildings, and more development underground. Urbanization can quickly increase the need for water resources management, because good sources of fresh water can become overused and polluted, and the amount of sewage can grow beyond what can be managed.

Government

Further information: Local government

Cities have local governments, which take different forms. Many are called a municipality, especially in England, the United States, and India. In France and Chile, a city may be a commune, and in Italy it may be a comune. The city's chief official is often called the "mayor". Even when a mayor has limited real power, they usually act as the figurehead of their city. City governments make many rules about everyday life, including health, transport, burial, resource use, recreation, and buildings. Cities usually provide municipal services such as education through school systems, policing through police departments, and firefighting through fire departments. Some services may be run by a higher level of government or by private companies.

Cities have traditionally paid for services mainly through property tax on land and buildings within the city. Paying for services and urban renewal is an ongoing challenge, so cities seek help from higher governments and work with the private sector. Some use privatization, corporatization, or financialization. Cities that have lost industry, or where wealthier people and businesses have moved beyond city limits, face the biggest problems. Many cities borrow money through a municipal bond, which is a loan with interest and a repayment date. Governance is broader than government and includes groups such as non-governmental organizations. Companies and multinational corporations now play a large role in many cities, and the people who lend money to cities pay close attention to credit ratings. Planning is covered in the next part.

Main articles: Urban planning and Urban design

Urban planning is the careful design of a city, including its land use, transport, and utilities. Government has the final legal say, but both public and private groups take part. Planning often involves choices where some people gain and others lose. The history of urban planning goes back to some of the earliest known cities, such as those in the Indus Valley and Mesoamerican civilizations, which were built on grids. Today, planned communities show planning most clearly, since they are designed completely before they are built.

Society

Cities are often divided into different areas. People who live close together may live, work, and play in separate places. They may also group together into ethnic or lifestyle areas, and areas of high poverty are sometimes called ghettoes. In the US, poverty is linked with the inner city, while in France it is linked with the banlieues. Suburbs and gated communities let wealthier people live in secure, exclusive neighborhoods. Landless urban workers, known as the proletariat, form a growing group in society, while peasants live in the countryside. Historically, cities have relied on rural areas for food grown through intensive farming, giving them money, government, manufactured goods, and culture in return. Cities have long been centers of retail commerce and shopping. Many cities that once grew through manufacturing now rely on a service economy, including tourism, hospitality, and entertainment.

Cities are typically hubs for education and the arts, with universities, museums, and temples. Tall skyscrapers have become iconic urban features. Cities also help people share news through newspapers and digital media. Today, many cities use place branding and city marketing to attract businesses, residents, and tourists. Some cities, such as Jerusalem, Mecca, and Rome, have long attracted pilgrims. Cities also compete to host the Olympic Games. Paris, a city known for its cultural history, hosted the most recent Olympics in the summer of 2024. Cities play a key role in war because of their economic, political, and symbolic importance, and many were founded under military rule and built with fortifications. During World War II, the Battle of Stalingrad showed how fighting in cities could be decisive. Cities have also been targets in asymmetric warfare, and some were completely destroyed. During the Cold War, some nuclear strategists even considered targeting cities to weaken an enemy.

Main article: Climate change and cities

Infrastructure

Urban infrastructure includes the physical networks and spaces a city needs for transportation, water, energy, recreation, and public life. These networks cost a lot to build at first, but they become cheaper to run for each extra user, so they are often treated as natural monopolies, where one organization, public or private, controls each network. Many infrastructure systems are built with extra links and pathways, so the whole system keeps working even when parts fail. Large projects such as airports, power plants, and railways, which are called megaprojects, need big funding from the national government or private companies. Infrastructure should serve all residents equally, but in some cities it is uneven.

Public utilities supply water, electricity, and communications to people. Sanitation is important for health in crowded cities, and it depends on water supply and waste management. Modern city life depends heavily on electricity, which powers machines, traffic lights, street lights, and telecommunications networks. People travel in cities to get to work, shops, and entertainment. They walk, use roads and walkways, or ride public transit such as streetcars and underground rail. Since the mid-20th century, cities have depended a lot on motor vehicles, which caused traffic problems, and severe traffic jams still happen in many cities. Today, walking and cycling are becoming more popular, and some cities limit car traffic.

See also: Public transport

Housing

Housing for residents is one of the biggest challenges every city must face. Good housing means more than just shelters. It also needs the physical systems people need to live and for businesses to work.

Homeownership shows a certain status and some economic security. In contrast, renting can use up much of the income of low-wage urban workers. Homelessness, which means not having a place to live, is a challenge that millions of people face today in both rich and poor countries. Because cities usually have more people living in each area than rural areas do, city residents are more likely to live in apartments and less likely to live in a single-family home.

Ecology

Main article: Urban ecology

Urban ecosystems are shaped by the many buildings, waste, and cultivation in gardens found in cities. These create conditions that do not exist in the wilderness, and in some cases they support rich biodiversity. Cities are home to immigrant plants and frequent changes to habitats, such as construction. Common city animals include insects, rodents, birds, cats, and dogs, while large predators are scarce. Cities also leave large ecological footprints because of their concentrated populations and technology. Air pollution comes from many sources, including internal combustion engines, and can form smog over cities. Urban soil also contains more heavy metals, such as lead, copper, and nickel. Cities create their own microclimates because concrete and asphalt heat up in sunlight. As a result, temperature in New York City is often higher than in nearby rural areas.

Poor and working-class people often face more environmental risks, a problem known as environmental racism when it is linked to racial segregation. One of the main ways to improve urban ecology is to add urban green spaces, such as parks, gardens, and trees, which help the health and well-being of people, animals, and plants. A 2019 study in Scientific Reports found that people who spent at least two hours a week in nature were more satisfied with their lives and more likely to be in good health than those who spent no time there.

World city system

As the world becomes more closely linked through globalization in economics, politics, technology, and culture, cities have come to play a leading role in affairs that cross national borders. They can go beyond what national governments do in international relations. This trend can be traced back to the Silk Road, Phoenicia, the Greek city-states, and the Hanseatic League and other alliances of cities. Today, the information economy, built on fast internet connections and telecommunication, lets cities connect instantly around the world, as well as through mass media.

A global city, also known as a world city, is a leading centre of trade, banking, finance, innovation, and markets. Saskia Sassen used the term in her 1991 work, The Global City: New York, London, Tokyo, to describe a city's power and status rather than its size. Global cities sit at the top of a ranking of the world's cities and use command and control through their economic and political influence. Critics, including Paul James, say the term is "reductive and skewed" because it focuses on financial systems. Multinational corporations and banks make their headquarters in global cities. Modern global cities, like New York City, often include large central business districts that serve as hubs for economic activity. Cities also take part in world politics on their own, apart from their nation-states, through sister city relationships and networks such as United Cities and Local Governments. On environmental issues like climate change, groups such as the C40 Cities Climate Leadership Group help cities work together. The United Nations System has held events and declarations on city development, including the Earth Summit in Rio de Janeiro and the Habitat III conference of 2016. UN-Habitat, the United Nations Human Settlements Programme, coordinates the UN urban agenda, and UNESCO focuses on cities as key sites for cultural governance.

Further information: Urban fiction

Cities have long been important in traditional Western culture. The Bible shows cities in both evil and holy forms, represented by Babylon and Jerusalem. In the Book of Genesis, Cain and Nimrod are the first city builders. In Sumerian mythology, Gilgamesh built the walls of Uruk. Cities can seem to be opposites: freeing and controlling, rich and poor, orderly and chaotic. Anti-urbanism is the name for ideas that oppose cities, either because of their culture or their political relationship with the country. This opposition may come from linking cities with oppression and the ruling elite. Political ideas strongly shape the stories and themes in discourse about cities, and cities in turn symbolize the societies they belong to.

Writers, painters, and filmmakers have created many works about city life. Old and medieval literature had a type called descriptiones that described city features and history. Modern writers such as Charles Dickens and James Joyce are known for vivid descriptions of their home cities. Fritz Lang came up with the idea for his famous 1927 film Metropolis while visiting Times Square and admiring its nighttime neon lighting. In the twentieth century, early films often showed cities as efficient places with smoothly working car traffic. By the 1960s, however, traffic congestion appeared in films such as The Fast Lady (1962) and Playtime (1967). Books, films, and other popular culture have also imagined future cities as both utopian and dystopian. As cities grow and connect more closely across the world, ideas such as Nylonkong (New York, London, Hong Kong) and a single world-covering ecumenopolis have appeared.