The word city and the related civilization come from the Latin root civĭtas, -ātis which originally meant "citizenship" or "member of the community" and which over time came to correspond with urbs, meaning "city" in a more physical sense.[26]​[16]​ The Roman civitas was closely linked to the Greek polis, another common root that appears in Spanish words such as metropolis.[27]​.

The history of the world's cities is generally long, given that the first cities would have emerged between fifteen to five thousand years ago, as permanent settlements that were not very complex. Sedentary societies that live in cities are often called civilizations. The branch of history and urban planning responsible for the study of cities and the urbanization process is urban history. The first true cities are sometimes considered those large permanent settlements where their inhabitants were no longer the simple owners of the areas near the settlement, but went on to work in more specialized occupations in the city, where trade, food provision and power were centralized.

Using this definition, the first known cities appeared in Mesopotamia (Ur, for example), along the Nile River, in the Indus Valley, and in China, approximately seven to five thousand years ago, generally resulting from the growth of small villages or the merger of small settlements. Before this time, settlements rarely reached any significant size, although there are exceptional cases such as Jericho "Jericho (West Bank)"), Çatal Höyük and Mehrgarh. Harappa and Mohenjo-Daro, both cities in the Indus Valley, were the most populous of these ancient cities, with a combined population estimated between 100 and 150 thousand inhabitants.

The growth of the ancient and medieval empires contributed to the appearance, in the Mediterranean Sea, of large capital cities and seats of provincial administration, such as Babylon "Babylon (city)"), Rome, Antioch, Alexandria, Carthage, Seleucia del Tigris, Pataliputra (located in present-day India), Chang'an (located in the present-day People's Republic of China), Constantinople (present-day Istanbul), and, later and successively, various cities. Chinese and Indian. Rome had more than a million inhabitants in the century BC. C., being considered by many as the only city to surpass this mark until the beginning of the Industrial Revolution. In ancient Rome, the area inhabited by citizens (cívis) was called a city (cívitas), who were those who had citizen rights, regardless of their activity (whether industry, agriculture or services). Other large administrative, commercial, industrial and ceremonial centers emerged in other areas, with Baghdad being considered the first city to break the million-inhabitant mark, held by Rome.

During the Middle Ages in Europe, a city was both a political-administrative entity and a group of houses. In medieval and Renaissance Spain, a city was the population that had no lord and was ruled directly by the king. He had the privilege of sending attorneys to the courts to negotiate the "Tasa (tribute)" rates and fees that could be imposed on him, in exchange for privileges. This classification of city was independent of size, thus, Madrid, capital of Spain since 1561, was not a city but a town "Villa (population)"), a status that it still retains. Some cities, exceptionally, such as Venice, Genoa or Lübeck, became powerful city-states, sometimes taking control of nearby lands or establishing extensive maritime empires. This phenomenon was not limited only to Europe, but there were cases such as that of Sakai "Sakai (Osaka)"), which had a considerable degree of autonomy in medieval Japan. In Europe, Venice, Rotterdam, Florence and Lisbon were considered the most important cities of this time, all of which grew alongside their ports and played an important role in commercial exchange.

As the city-states located on the coasts of the Mediterranean and the Baltic Sea began to disappear from the 19th century onwards, the great European capitals benefited from the increase in trade that arose from the colonization of America and the establishment of a transatlantic economy. By the end of the century, London had become the largest city in the world, with a population approaching one million, with Paris, Baghdad, Beijing, Istanbul and Kyoto as other large cities. But it was the beginning of the Industrial Revolution and the growth of modern industry, at the end of the century, that allowed massive urbanization and the emergence of new large cities, first in Europe, and then in other regions, as the new opportunities generated in cities caused a large number of emigrants from rural communities to settle in urban areas.

Geography

Currently, large cities are much larger and more populous than in times past. An example is Paris, which in 1400, had 225 thousand inhabitants in 8 km² of area. Today, the city has 2.2 million inhabitants and 105 km², and its metropolitan region has more than 11.2 million inhabitants and 14,518 km² of area.

In the United States and Canada, the most common pattern of public roads is the hippodamic or checkerboard plan, that is, road arteries running parallel to each other, with other parallel streets cutting them perpendicularly. This system was also used for thousands of years in China, and by the Spanish when founding cities in America. In Europe, since most cities were not planned in advance, their system of public roads, streets and avenues spread unorganized throughout the city. Many of the walls that surrounded ancient European cities gave rise to modern high-capacity public roads.

Commonly, large cities have a financial district, where financial institutions, headquarters of large companies and shopping centers are located. People from all over the city (as well as neighboring cities) come to this financial center to work daily. This is generally small in area, but can house up to tens of thousands of jobs, thanks to the existence of skyscrapers. The City of London region itself, for example, the financial center of the metropolitan region of London, has 2900 km² and 8.6 million permanent inhabitants, and more than 300 thousand people from other places in the metropolitan region go to the City to work every day.

Administration

The administration of cities corresponds to different institutions, depending on each country. Among the most common names used to designate the administrative body of a city are municipality, town hall and prefecture. These organizations are responsible for city planning, and according to the powers given by the respective national legislation, they can be responsible for the administration of the public transportation system, the school system and public libraries, police and fire departments. The administration of a city is generally headed by a mayor or municipal president and a council, all elected by popular vote (in democratic regimes). He is usually in charge of looking after the interests of his fellow citizens, representing them before the highest hierarchical authority, in addition to promoting local policies to improve their quality of life, such as health or sports programs, and fighting crime, among other various tasks. Its budget generally comes from national funds and certain own revenues, such as trade permits, building permits or specific taxes.

Some large cities are usually subdivided administratively into communes, neighborhoods, districts, delegations "Delegations of the Federal District (Mexico)") or districts.

Economy

Currently, the economy of cities is general and highly diversified, varying between cities. Since the urban economy is never based solely on a certain economic sector, several cities depend mainly on a single, or a few, economic sectors. Some cities, however, still rely heavily on agriculture and ranching, such as Saskatoon. The economy of large cities tends to be more diversified, but this does not always happen. In larger cities, the manufacturing industry is almost always one of the main sources of income, generating thousands of jobs, although industry is currently no longer the largest economic activity in cities, transferring this position to the services sector. In several large cities, thousands of people work daily in offices and financial institutions. Cities such as New York, Tokyo, London, Paris and Hong Kong are large financial centers, where this activity is the main source of income for the city. In other cities, such as Rome, Quebec and Foz do Iguazú, they depend greatly on tourism. Various cities have a highly diversified economy, that is, where all sectors have approximately the same importance, so they are less vulnerable to economic recessions compared to those cities that depend on a particular economic sector.

Metropolis

A metropolis is a large population center, consisting of a large central city (sometimes two or more) and its adjacent area of ​​influence, made up of other smaller and relatively close cities and towns. Generally, metropolises form conurbations, forming a single urban area. For example, Mexico City is a central city, and with Naucalpan, Ecatepec de Morelos, Tultitlán and other adjacent towns together they form a conurbation, known as the "Metropolitan Zone of the Valley of Mexico."

However, a metropolis does not necessarily need to be made up of a single contiguous urbanized area, and the union of two or more urbanized areas interspersed with rural areas may be designated as a metropolis. The cities that form a metropolis have a high degree of integration with each other. A region made up of various metropolises located close to each other are known as megalopolises. Currently, the most populous metropolises in the world, which have between 10 and 40 million inhabitants, are Tokyo, Mexico City, Seoul, New York, Buenos Aires and São Paulo.

Urban growth

According to reliable calculations, the growth of the urban population is astonishing, exceeding one million people weekly. More than two hundred cities in developing countries have more than one million inhabitants, and there are about twenty metropolises with more than ten million residents. Furthermore, the increase is not expected to slow down. According to a report by the Worldwatch Institute), the Nigerian city of Lagos “will have 25,000,000 inhabitants in 2015, making the thirteenth largest city in the world the third largest.”

Global cities

A global city is a large banking, commercial, financial, political and industrial center. The term global city (not to be confused with megalopolis or megacity) was invented by sociologist Saskia Sassen in 1991. The expression megacity refers to a large urban area, while a global city is distinguished by its great influence at a regional, national and international level. Global cities, according to Sassen, have more similar characteristics among themselves than with other cities in the same country.[29]​.

The notion of a global city views the city as a container where skills and resources are concentrated. The more a city is able to concentrate skills and resources, the more prosperous and powerful it is, becoming powerful enough to influence what happens around the world. Critics of this notion allege the ambiguity of the expression "power." In a global city, power refers primarily to economic and political power and therefore may not include cities that are powerful in other ways. For example, cities like Rome or Jerusalem are powerful in historical and religious terms.

In 2000, municipal leaders signed the Aalborg Charter, a community initiative known as Agenda 21, which promoted the sustainable development of cities under environmental principles. The main guiding guidelines for the actions to be undertaken were focused on the cycles of natural resources in cities, the quality of the urban environment and territorial and urban planning. Regarding the quality of the urban environment specifically, actions should be aimed at improving and protecting the urban natural environment with adequate land use planning, the creation of parks, green and social use areas and the recovery of spaces of interest. This Agenda 21 arises out of concern about massive global urbanization. It is expected that within 35 years the number of people living in cities will multiply by three, which makes a change necessary to guarantee the quality of life in future cities.

Traditionally, parks have fulfilled three functions: satisfying the recreational and leisure demands of citizens, improving the quality of life and helping to structure the urban fabric. These functions are of vital importance for the life of the population within cities, however, although the social consideration of these green areas is very positive, greater involvement is necessary on the part of all actors (government institutions, citizens and the media) to ensure that parks contribute effectively to the sustainability of cities.

The difference between town, village and city is understood differently in different parts of the world. Some languages ​​have a tripartite distinction, such as the Iberian languages ​​Portuguese and Spanish, for example: vila (village), povo (town), and cidade (city).

Others have a bipartite distinction, such as French: village (town) and ville (city).

Although in the Spanish-speaking world, there is no universal consensus on the exact distinctions. The term can be used for towns endowed with city status, or for a town that exercises control over other neighboring towns. However, the terms are usually understood like this in the Spanish-speaking world:.

The definition is blurry, because historically the administration was understood in a religious way, that is: in the village there were unattended hermitages, in the towns there were parishes with priests shared with other towns, in the towns there were permanent priests and in the cities there were religious authorities (bishop). As administration became more secular in the Spanish-speaking world, this historical definition has lost meaning and the use of the terms is now somewhat ambiguous.

Although city can refer to an agglomeration, suburbs and even satellites, it does not apply to a conurbation (group) of distinct urban areas, nor to a metropolitan area.

A city is distinguished from other human settlements by its relatively large size, but also by its functions and its special symbolic status, which may be granted by a central authority. The term can also refer to both the physical streets and buildings of the city and the group of people who live there, and can be used in a general sense to refer to an urban rather than a rural territory.[16]​[17]​.

National "Census (statistics)" censuses use a variety of definitions (invoking factors such as population, population density, number of dwellings, economic function, and infrastructure) to classify populations as urban. Typical definitions for small city populations start at around 100,000 people.[18] Common population definitions for an urban area (city or town) range from 1,500 to 50,000 people, with most US states using a minimum of between 1,500 and 5,000 people.[19] Some jurisdictions do not set such minimums.[20] In the United Kingdom, the status city status is granted by the Crown and then remains permanent. Historically, the qualifying factor was the presence of a cathedral, resulting in some very small towns such as Wells, with a population of 12,000 in 2018, and St Davids, with a population of 1,751 in 2021. Under the "functional definition", a town is distinguished not only by its size, but also by the role it plays within a wider political context. Cities serve as administrative, commercial, religious and cultural centers for their larger surrounding areas.[21]​.

The presence of a literate elite is often associated with cities due to the cultural diversities present in a city.[22][23] A typical city has professional administrators, regulations, and some form of taxes to support government workers. This arrangement contrasts with the more typically horizontal relationships in a tribe or village that achieves common goals through informal agreements between neighbors or the leadership of a chief. Governments may be based on heredity, religion, military power, work systems such as canal construction, food distribution, land ownership, agriculture, trade, manufacturing, finance, or a combination of these. Societies that live in cities are often called civilizations.

The degree of urbanization is a modern metric that helps define what comprises a city: "a population of at least 50,000 inhabitants in contiguous dense grid cells (>1,500 inhabitants per square kilometer)."[24] This metric was "devised over the years by the European Commission, the OECD, the World Bank and others, and approved in March [2021] by the United Nations... largely with the purpose of making international statistical comparisons".[25]​.

The word city and the related civilization come from the Latin root civĭtas, -ātis which originally meant "citizenship" or "member of the community" and which over time came to correspond with urbs, meaning "city" in a more physical sense.[26]​[16]​ The Roman civitas was closely linked to the Greek polis, another common root that appears in Spanish words such as metropolis.[27]​.

The history of the world's cities is generally long, given that the first cities would have emerged between fifteen to five thousand years ago, as permanent settlements that were not very complex. Sedentary societies that live in cities are often called civilizations. The branch of history and urban planning responsible for the study of cities and the urbanization process is urban history. The first true cities are sometimes considered those large permanent settlements where their inhabitants were no longer the simple owners of the areas near the settlement, but went on to work in more specialized occupations in the city, where trade, food provision and power were centralized.

Using this definition, the first known cities appeared in Mesopotamia (Ur, for example), along the Nile River, in the Indus Valley, and in China, approximately seven to five thousand years ago, generally resulting from the growth of small villages or the merger of small settlements. Before this time, settlements rarely reached any significant size, although there are exceptional cases such as Jericho "Jericho (West Bank)"), Çatal Höyük and Mehrgarh. Harappa and Mohenjo-Daro, both cities in the Indus Valley, were the most populous of these ancient cities, with a combined population estimated between 100 and 150 thousand inhabitants.

The growth of the ancient and medieval empires contributed to the appearance, in the Mediterranean Sea, of large capital cities and seats of provincial administration, such as Babylon "Babylon (city)"), Rome, Antioch, Alexandria, Carthage, Seleucia del Tigris, Pataliputra (located in present-day India), Chang'an (located in the present-day People's Republic of China), Constantinople (present-day Istanbul), and, later and successively, various cities. Chinese and Indian. Rome had more than a million inhabitants in the century BC. C., being considered by many as the only city to surpass this mark until the beginning of the Industrial Revolution. In ancient Rome, the area inhabited by citizens (cívis) was called a city (cívitas), who were those who had citizen rights, regardless of their activity (whether industry, agriculture or services). Other large administrative, commercial, industrial and ceremonial centers emerged in other areas, with Baghdad being considered the first city to break the million-inhabitant mark, held by Rome.

During the Middle Ages in Europe, a city was both a political-administrative entity and a group of houses. In medieval and Renaissance Spain, a city was the population that had no lord and was ruled directly by the king. He had the privilege of sending attorneys to the courts to negotiate the "Tasa (tribute)" rates and fees that could be imposed on him, in exchange for privileges. This classification of city was independent of size, thus, Madrid, capital of Spain since 1561, was not a city but a town "Villa (population)"), a status that it still retains. Some cities, exceptionally, such as Venice, Genoa or Lübeck, became powerful city-states, sometimes taking control of nearby lands or establishing extensive maritime empires. This phenomenon was not limited only to Europe, but there were cases such as that of Sakai "Sakai (Osaka)"), which had a considerable degree of autonomy in medieval Japan. In Europe, Venice, Rotterdam, Florence and Lisbon were considered the most important cities of this time, all of which grew alongside their ports and played an important role in commercial exchange.

As the city-states located on the coasts of the Mediterranean and the Baltic Sea began to disappear from the 19th century onwards, the great European capitals benefited from the increase in trade that arose from the colonization of America and the establishment of a transatlantic economy. By the end of the century, London had become the largest city in the world, with a population approaching one million, with Paris, Baghdad, Beijing, Istanbul and Kyoto as other large cities. But it was the beginning of the Industrial Revolution and the growth of modern industry, at the end of the century, that allowed massive urbanization and the emergence of new large cities, first in Europe, and then in other regions, as the new opportunities generated in cities caused a large number of emigrants from rural communities to settle in urban areas.

Geography

Currently, large cities are much larger and more populous than in times past. An example is Paris, which in 1400, had 225 thousand inhabitants in 8 km² of area. Today, the city has 2.2 million inhabitants and 105 km², and its metropolitan region has more than 11.2 million inhabitants and 14,518 km² of area.

In the United States and Canada, the most common pattern of public roads is the hippodamic or checkerboard plan, that is, road arteries running parallel to each other, with other parallel streets cutting them perpendicularly. This system was also used for thousands of years in China, and by the Spanish when founding cities in America. In Europe, since most cities were not planned in advance, their system of public roads, streets and avenues spread unorganized throughout the city. Many of the walls that surrounded ancient European cities gave rise to modern high-capacity public roads.

Commonly, large cities have a financial district, where financial institutions, headquarters of large companies and shopping centers are located. People from all over the city (as well as neighboring cities) come to this financial center to work daily. This is generally small in area, but can house up to tens of thousands of jobs, thanks to the existence of skyscrapers. The City of London region itself, for example, the financial center of the metropolitan region of London, has 2900 km² and 8.6 million permanent inhabitants, and more than 300 thousand people from other places in the metropolitan region go to the City to work every day.

Administration

The administration of cities corresponds to different institutions, depending on each country. Among the most common names used to designate the administrative body of a city are municipality, town hall and prefecture. These organizations are responsible for city planning, and according to the powers given by the respective national legislation, they can be responsible for the administration of the public transportation system, the school system and public libraries, police and fire departments. The administration of a city is generally headed by a mayor or municipal president and a council, all elected by popular vote (in democratic regimes). He is usually in charge of looking after the interests of his fellow citizens, representing them before the highest hierarchical authority, in addition to promoting local policies to improve their quality of life, such as health or sports programs, and fighting crime, among other various tasks. Its budget generally comes from national funds and certain own revenues, such as trade permits, building permits or specific taxes.

Some large cities are usually subdivided administratively into communes, neighborhoods, districts, delegations "Delegations of the Federal District (Mexico)") or districts.

Economy

Currently, the economy of cities is general and highly diversified, varying between cities. Since the urban economy is never based solely on a certain economic sector, several cities depend mainly on a single, or a few, economic sectors. Some cities, however, still rely heavily on agriculture and ranching, such as Saskatoon. The economy of large cities tends to be more diversified, but this does not always happen. In larger cities, the manufacturing industry is almost always one of the main sources of income, generating thousands of jobs, although industry is currently no longer the largest economic activity in cities, transferring this position to the services sector. In several large cities, thousands of people work daily in offices and financial institutions. Cities such as New York, Tokyo, London, Paris and Hong Kong are large financial centers, where this activity is the main source of income for the city. In other cities, such as Rome, Quebec and Foz do Iguazú, they depend greatly on tourism. Various cities have a highly diversified economy, that is, where all sectors have approximately the same importance, so they are less vulnerable to economic recessions compared to those cities that depend on a particular economic sector.

Metropolis

A metropolis is a large population center, consisting of a large central city (sometimes two or more) and its adjacent area of ​​influence, made up of other smaller and relatively close cities and towns. Generally, metropolises form conurbations, forming a single urban area. For example, Mexico City is a central city, and with Naucalpan, Ecatepec de Morelos, Tultitlán and other adjacent towns together they form a conurbation, known as the "Metropolitan Zone of the Valley of Mexico."

However, a metropolis does not necessarily need to be made up of a single contiguous urbanized area, and the union of two or more urbanized areas interspersed with rural areas may be designated as a metropolis. The cities that form a metropolis have a high degree of integration with each other. A region made up of various metropolises located close to each other are known as megalopolises. Currently, the most populous metropolises in the world, which have between 10 and 40 million inhabitants, are Tokyo, Mexico City, Seoul, New York, Buenos Aires and São Paulo.

Urban growth

According to reliable calculations, the growth of the urban population is astonishing, exceeding one million people weekly. More than two hundred cities in developing countries have more than one million inhabitants, and there are about twenty metropolises with more than ten million residents. Furthermore, the increase is not expected to slow down. According to a report by the Worldwatch Institute), the Nigerian city of Lagos “will have 25,000,000 inhabitants in 2015, making the thirteenth largest city in the world the third largest.”

Global cities

A global city is a large banking, commercial, financial, political and industrial center. The term global city (not to be confused with megalopolis or megacity) was invented by sociologist Saskia Sassen in 1991. The expression megacity refers to a large urban area, while a global city is distinguished by its great influence at a regional, national and international level. Global cities, according to Sassen, have more similar characteristics among themselves than with other cities in the same country.[29]​.

The notion of a global city views the city as a container where skills and resources are concentrated. The more a city is able to concentrate skills and resources, the more prosperous and powerful it is, becoming powerful enough to influence what happens around the world. Critics of this notion allege the ambiguity of the expression "power." In a global city, power refers primarily to economic and political power and therefore may not include cities that are powerful in other ways. For example, cities like Rome or Jerusalem are powerful in historical and religious terms.

In 2000, municipal leaders signed the Aalborg Charter, a community initiative known as Agenda 21, which promoted the sustainable development of cities under environmental principles. The main guiding guidelines for the actions to be undertaken were focused on the cycles of natural resources in cities, the quality of the urban environment and territorial and urban planning. Regarding the quality of the urban environment specifically, actions should be aimed at improving and protecting the urban natural environment with adequate land use planning, the creation of parks, green and social use areas and the recovery of spaces of interest. This Agenda 21 arises out of concern about massive global urbanization. It is expected that within 35 years the number of people living in cities will multiply by three, which makes a change necessary to guarantee the quality of life in future cities.

Traditionally, parks have fulfilled three functions: satisfying the recreational and leisure demands of citizens, improving the quality of life and helping to structure the urban fabric. These functions are of vital importance for the life of the population within cities, however, although the social consideration of these green areas is very positive, greater involvement is necessary on the part of all actors (government institutions, citizens and the media) to ensure that parks contribute effectively to the sustainability of cities.

The difference between town, village and city is understood differently in different parts of the world. Some languages ​​have a tripartite distinction, such as the Iberian languages ​​Portuguese and Spanish, for example: vila (village), povo (town), and cidade (city).

Others have a bipartite distinction, such as French: village (town) and ville (city).

Although in the Spanish-speaking world, there is no universal consensus on the exact distinctions. The term can be used for towns endowed with city status, or for a town that exercises control over other neighboring towns. However, the terms are usually understood like this in the Spanish-speaking world:.

The definition is blurry, because historically the administration was understood in a religious way, that is: in the village there were unattended hermitages, in the towns there were parishes with priests shared with other towns, in the towns there were permanent priests and in the cities there were religious authorities (bishop). As administration became more secular in the Spanish-speaking world, this historical definition has lost meaning and the use of the terms is now somewhat ambiguous.

Although city can refer to an agglomeration, suburbs and even satellites, it does not apply to a conurbation (group) of distinct urban areas, nor to a metropolitan area.