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 have 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 work with each other. This can help many groups, such as by making it easier to deliver goods and services. Cities around the world include Lagos, which is one of the fastest-growing megacities, Tokyo, Paris, Rio de Janeiro, Manhattan, Delhi, Hong Kong, and São Paulo.

Long ago, city dwellers were only a small part of humanity. In the last two hundred years, cities have grown very quickly, and more than half of the world population now lives in cities. This has had big effects on global sustainability. Today's cities usually form the centre of larger metropolitan areas and urban areas. Many commuters travel toward city centres for work, fun, and school. 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 this, the international community has made building sustainable cities a priority through Sustainable Development Goal 11. Dense cities use less land, and transportation in them can be more efficient. This means 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, having many people in one place can also cause problems, such as urban heat islands, pollution in one area, and strain on water supplies and other resources.

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

Meaning

An urban area can be a city or a town. Its population minimum is often between 1,500 and 50,000 people. Most U.S. states use a minimum between 1,500 and 5,000 people, and some places have no such rule. National censuses look at things like population density, the number of dwellings, economic role, and infrastructure to decide which populations are urban.

A city stands out because of its large size, its jobs, and its special symbolic status. The word can describe the streets and buildings, or the people who live there. It can also mean urban instead of rural territory. In the "functional definition," a city is known for its role in a wider political area. It serves as a center for government, trade, religion, and culture for the places around it. Cities usually have professional administrators, rules, and some kind of taxation to pay government workers. This is different from the more horizontal way 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 is a modern measure. The European Commission, OECD, World Bank, and others use it. It counts a city as having at least 50,000 people in dense areas. The United Nations approved this measure in March 2021. Working definitions for small cities often start at around 100,000 people.

In Australia, what counts as a city can be different in each state. In the United Kingdom, city status used to be limited to towns with diocesan cathedrals. Today it is given by the Crown and usually lasts forever, with two exceptions. Because of this older rule, some cities are very small, such as St Davids, which had 1,751 people in 2021.

Etymology

The word city comes from the Old French word cité. That word came from the Latin word civitas, which meant "citizenship" or "state". The related word civilization may also come from the Latin root civitas. At first, this word meant "citizenship" or "community member." 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.

The names of individual cities and towns are called astionyms in toponymic terminology. This word comes from two Ancient Greek words: "city or town" (ἄστυ) and "name" (ὄνομα).

Geography

Urban geography looks at cities in two ways: how they fit into the land around them, and how they are laid out inside. Cities cover about 3% of the Earth's land. Over time, people chose town sites based on nature, technology, trade, and defense. Water has long been very important. Although rail transport in the 1800s allowed some exceptions, most of the world's city people today live near the coast or on a river. Cities usually cannot produce their own food, so they depend on a relationship with a hinterland, the countryside that supports them. Only special cases, such as mining towns that play a key part in long-distance trade, are cut off from the land that feeds them.

Most cities have a central area with important buildings for business, government, and religion. Archaeologists call this area by the Greek word temenos. If it has walls, it is called a citadel. These spaces show how important the city was to the area around it, its sphere of influence. Today, many cities have a city center or downtown, which sometimes overlaps with a central business district. Cities also have public spaces where anyone can go. Some are privately owned spaces open to the public, some are in the public domain, and others are part of the commons. Since the time of the Greek agora, Western philosophy has seen physical public space as the foundation of the public sphere, where people share ideas. Public art decorates these spaces, though not always in a way everyone likes. Parks and natural sites within cities give people a break from the hard, regular shapes of built environments. Urban green spaces also help cool the city, especially in warm climates.

The urban structure often follows one or more basic patterns: geomorphic, radial, concentric, rectilinear, and curvilinear. The land usually shapes how a city is built, but cities can also form patterns through city planning. In radial cities, main roads meet at a central point. Old town walls and citadels can show where earlier city edges were, and later ring roads often added to them. Dutch cities such as Amsterdam and Haarlem have a central square surrounded by rings of canals. Moscow also shows a similar pattern clearly. The grid plan, with straight streets, has been used for thousands of years. The Indus Valley Civilization built Mohenjo-Daro and Harappa on a grid, following ideas described by Kautilya and lined up with the compass points. The ancient Greek city of Priene also shows a grid plan, with special districts, across the Hellenistic Mediterranean.

Towns and built-up areas often spread well beyond the city proper. This is sometimes called urban sprawl. Metropolitan areas include suburbs and exurbs, which grow around commuters who travel to work. Some edge cities have a good deal of economic and political independence. In the US, these areas are grouped into metropolitan statistical areas for studying demography and marketing. Some cities join together into one connected landscape called an urban agglomeration, conurbation, or megalopolis. An example is the BosWash corridor in 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. They did not grow in a simple, straight line. They began from proto-urban settlements, such as Çatalhöyük. Some places, including Jericho, Aleppo, Byblos, Damascus, and Athens, are believed to have had people living in them for a very long time. Most archaeologists think the Mesopotamian city of Uruk, from about 3500 BC, was the first true city. Early cities often had granaries to store food. Many were built where people could farm and trade. Great civilizations grew up along river valleys in the ancient world, such as Mohenjo-daro in the Indus Valley. Rome was the first city to reach one million people. Cities also grew in the Andes, Mesoamerica, and West Africa. Some of them, such as Mexico City, are still home to many people today.

In the Middle Ages, the Khmer capital of Angkor became one of the largest settlements in the world before machines were used for work. Cities such as Timbuktu became rich through trade. In Europe, cities such as those in the Hanseatic League joined together to protect themselves and to trade. Later, factories and industry led many people to move from the countryside into cities. This is called urbanization. It brought problems such as overcrowding and poor sanitation. In the late 20th century, some industrial cities, such as Detroit, began to get smaller. Today, new High technology has helped some cities become centres of knowledge and learning. Some companies have also proposed building new, Master-planned cities.

Main article: Urbanization

Urbanization is the process of people moving from the countryside to cities. People move for political, economic, and cultural reasons. Until the 1700s, there was a balance between farming villages and towns with markets and small workshops. With the agricultural and industrial revolutions, cities grew quickly. People moved in from other places, and more babies were born in cities. In England, the share of people living in cities grew from 17% in 1801 to 72% in 1891. In 1900, 15% of the world's people lived in cities. Cities also attract people because of their culture. Urbanization spread quickly across Europe and the Americas. Since the 1950s, it has also grown 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 lived in cities. Latin America is the most urban continent. About four out of five people there live in cities, and about one in five lives in shantytowns (favelas, poblaciones callampas, and similar areas). Batam, Indonesia, Mogadishu, Somalia, Xiamen, China, and Niamey, Niger, are among the cities growing fastest. Cities in the more developed countries of the "Global North" are still more urban than those in the less developed countries of the "Global South." However, the gap is getting smaller, because cities in the Global South are growing faster. Asia has by far the most city dwellers, with over two billion people. The UN expects 2.5 billion more people to live in cities worldwide by 2050. Most of this growth will happen in Asia and Africa. Megacities, which are cities with millions of people, have grown in number, especially in Asia, Africa, and Latin America. Money from other countries helps these cities grow. Businesses move there from Europe and North America through the relocation of major businesses, and immigrants arrive from near and far. Many of these cities have a very wealthy group of people who live in gated communities. Many other people live in poor housing with weak basic services. Cities have also grown outward, covering more land, with more tall buildings and more building underground. Fast growth can quickly increase the need for water resources management. Good sources of fresh water can be used up and polluted. The amount of sewage can also grow beyond what can be managed.

Government

Further information: Local government

Cities have local governments, and these can look different from place to place. Many are called a municipality, especially in England, the United States, and India. In France and Chile, a city may be called a commune, and in Italy it may be a comune. The city's leader is often called the "mayor". Even when a mayor has little real power, they usually act as the figurehead of the city. City governments make rules about everyday life, such as 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 mostly paid for services through property tax on land and buildings in the city. Paying for services and urban renewal is an ongoing challenge, so cities ask higher governments for help 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, often have the biggest problems. Many cities borrow money through a municipal bond, which is a loan that pays interest and has a date for repayment. 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 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, transport, and utilities. Government has the final legal say, but both public and private groups take part. Planning often involves choices that help some people and hurt others. 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 fully designed 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. Some people also group together in ethnic or lifestyle areas. Areas where many people are poor are sometimes called ghettoes. In the US, poverty is often linked with the inner city, while in France it is linked with the banlieues. Suburbs and gated communities let wealthier people live in safe, private neighborhoods. Urban workers who do not own land, known as the proletariat, form a growing group in society. Peasants live in the countryside. In the past, cities relied on rural areas for food grown through intensive farming. In return, cities gave money, government, manufactured goods, and culture. Cities have long been centers of retail business and shopping. Many cities that once grew through manufacturing now depend on a service economy. This includes tourism, hospitality, and entertainment.

Cities are often centers of learning and art. They have universities, museums, and temples. Tall skyscrapers have become well-known features of cities. 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 visitors. Some cities, such as Jerusalem, Mecca, and Rome, have long drawn pilgrims. Cities also compete to host the Olympic Games. Paris, a city known for its history and culture, hosted the most recent Olympics in the summer of 2024. Cities have often played an important part in war. Many were built with fortifications to protect them. During World War II, the Battle of Stalingrad showed how fighting in cities could decide the outcome. Some cities have been targets in asymmetric warfare, and some were badly damaged. During the Cold War, some nuclear strategists even thought about targeting cities.

Main article: Climate change and cities

Infrastructure

Urban infrastructure includes the networks and spaces a city needs. These cover transportation, water, energy, parks, and public places. These networks cost a lot to build, but each new user adds little cost to run. Because of this, they are often natural monopolies, where one organization, public or private, runs each network. Many systems have extra links and paths, so the city keeps working even when one part breaks. Big projects like airports, power plants, and railways are called megaprojects. They need a lot of money from the national government or private companies. Everyone in a city should have equal access to infrastructure, but in some cities it is not equal.

Public utilities bring water, electricity, and communication services to people. Sanitation keeps people healthy in crowded cities. It depends on water supply and waste management. City life depends a lot on electricity, which powers machines, traffic lights, street lights, and telecommunications networks. People travel in cities to get to work, shops, and fun places. They walk, use roads and walkways, or take public transit, such as streetcars and underground trains. Since the mid-20th century, many cities have relied heavily on cars. This has caused traffic problems, and big traffic jams still happen in many cities. Today, more people are walking and cycling, and some cities limit car traffic.

See also: Public transport

Housing

Housing is one of the biggest challenges every city has. Good housing is more than just a shelter. It also needs the basic systems people need to live, and the systems businesses need to work.

Owning a home can show a certain status and some financial security. Renting, on the other hand, can take up much of the money earned by people with low-paying jobs in cities. Homelessness, which means not having a place to live, is a problem many people face today in both rich and poor countries. Because cities usually have more people living in each area than the countryside does, city residents are more likely to live in apartments and less likely to live in a single-family home.

Ecology

Main article: Urban ecology

Buildings, waste, and gardens where people grow plants shape the living things in cities. These conditions are very different from the wilderness. In some cases, cities support a rich variety of life, or biodiversity. Cities are home to immigrant plants, and habitats often change, for example when new buildings are built. Common city animals include insects, rodents, birds, cats, and dogs. Large predators are rare. Cities also have a large ecological footprint because so many people live close together and use a lot of technology. Air pollution comes from many sources, including internal combustion engines. It can form smog over cities. Urban soil often contains more heavy metals, such as lead, copper, and nickel. Cities can also be warmer than the areas around them. Concrete and asphalt heat up in sunlight, creating their own microclimates. For example, temperature in New York City is often higher than in nearby countryside.

Poor and working-class people often face more environmental risks. When this is linked to racial segregation, it is called environmental racism. One of the main ways to improve urban ecology is to add urban green spaces, such as parks, gardens, and trees. These spaces help people, animals, and plants stay healthy. 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. They were also more likely to be in good health than people who spent no time there.

World city system

As the world becomes more connected through globalization in business, politics, technology, and culture, cities now play a major role in matters that cross national borders. They can do things that go beyond what national governments do in international relations. This trend goes back to the Silk Road, Phoenicia, the Greek city-states, and the Hanseatic League and other groups of cities that worked together. Today, the information economy, which relies on fast internet and telecommunication, lets cities connect quickly with each other around the world, and through mass media.

A global city, also called a world city, is a leading center of trade, banking, finance, new ideas, and markets. Saskia Sassen used the term in her 1991 book, The Global City: New York, London, Tokyo. She used it to describe a city's power and importance, not its size. Global cities are at the top of the world's city rankings. They have a strong influence on the economy and politics through command and control. Some critics, including Paul James, say the term is "reductive and skewed" because it focuses mainly on money systems. Multinational corporations and banks often have their main offices in global cities. Large modern global cities, like New York City, often have big central business districts where much of the business happens. Cities also take part in world affairs on their own, separate from their countries, through sister city relationships and networks like United Cities and Local Governments. To work 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 meetings and made agreements about city growth, including the Earth Summit in Rio de Janeiro and the Habitat III conference in 2016. UN-Habitat, the United Nations Human Settlements Programme, organizes the UN's work on cities, and UNESCO sees cities as important places for cultural governance.

Further information: Urban fiction

Cities have been important in traditional Western culture for a long time. The Bible describes cities in both bad and holy ways, through Babylon and Jerusalem. In the Book of Genesis, Cain and Nimrod are the first city builders. In Sumerian stories, Gilgamesh built the walls of Uruk. Cities can seem like opposites: they can give freedom and also bring control, they can be rich and poor, and they can be 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 unfair rule and the ruling elite. Political ideas strongly shape the stories and themes in discourse about cities, and cities in turn reflect the societies they belong to.

Writers, painters, and filmmakers have created many works about city life. Old and medieval writing had a type called descriptiones that described a city's features and history. Later 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 bright nighttime neon lighting. In the twentieth century, early films often showed cities as efficient places where car traffic moved smoothly. By the 1960s, however, traffic congestion appeared in films such as The Fast Lady (1962) and Playtime (1967). Books, films, and other popular stories 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 city covering the whole planet, called an ecumenopolis, have appeared.