Urban area in the context of "Civilization"

Two thirds of the Greek people live in urban areas. Greece's largest metropolitan centers and most influential urban areas are those of Athens and Thessaloniki, with metropolitan populations of approximately four million and 990 thousand inhabitants respectively. The third-largest city is Patras, with a metropolitan area of approximately 250,000 inhabitants. The table below lists the largest cities in Greece, by population size, using the official census results of 1991, 2001, 2011 and 2021.

This is a list of urban areas in the European Union with over 500,000 inhabitants as of 2022. The data comes from Demographia and the United Nations Department of Economic and Social Affairs. Demographia provides figures for urban areas (including conurbations), while the UN DESA figures are a mix agglomerations, cities proper and metropolitan areas. For comparison, Function Urban Area (FUA) population figures by Eurostat are also provided, however, these measure the wider metropolitan areas.

A cradle of civilization is a location and a culture where civilization was developed independently of other civilizations in other locations. A civilization is any complex society characterized by the development of the state, social stratification, urbanization, and symbolic systems of communication beyond signed or spoken languages (namely, writing systems and graphic arts).

Scholars generally acknowledge six cradles of civilization: Mesopotamia, Ancient Egypt, Ancient India and Ancient China are believed to be the earliest in Afro-Eurasia, while the Caral–Supe civilization of coastal Peru and the Olmec civilization of Mexico are believed to be the earliest in the Americas. All of the cradles of civilization depended upon agriculture for sustenance (except possibly Caral–Supe which may have depended initially on marine resources). All depended upon farmers producing an agricultural surplus to support the centralized government, political leaders, religious leaders, and public works of the urban centers of the early civilizations.

The United Nations uses three definitions for what constitutes a city, as not all cities in all jurisdictions are classified using the same criteria. Cities may be defined as the cities proper, their metropolitan regions, or the extent of their urban area. A complicating factor is that many large cities in the world have not only homeless or the unhoused, but also vast slum communities. This leads to official census data being less accurate in representing the actual number of residents in a given area.

A city is a human settlement of a substantial size. The term "city" has different meanings around the world and in some places the settlement can be very small. Even where the term is limited to larger settlements, there is no universally agreed definition of the lower boundary for their size. In a narrower sense, a city can be defined as a permanent and densely populated 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 organizations, and businesses, sometimes benefiting different parties in the process, such as improving the 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 areas and urban areas—creating numerous commuters traveling toward city centres 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, climate change, and global health. Because of these major influences on global issues, the international community has prioritized investment in sustainable cities through Sustainable Development Goal 11. Due to the efficiency of transportation and the smaller land consumption, dense cities hold the potential to have a smaller ecological footprint per inhabitant than more sparsely populated areas. Therefore, compact cities are often referred to as a crucial element in fighting climate change. However, this concentration can also have some significant harmful effects, such as forming urban heat islands, concentrating pollution, and stressing water supplies and other resources.

A conurbation is a region consisting of 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 cases, a conurbation is a polycentric urbanised area in which transportation has developed to link areas. They create a single urban labour market or travel to work area.

Conurbations often emerged in coal-mining regions during the period of the Industrial Revolution.Patrick Geddes coined the term in his book Cities in Evolution (1915). He drew attention to the ability of the new technology at the time of electric power and motorised transport to allow cities to spread and agglomerate together, and gave as examples "Midlandton" in England, the Ruhr in Germany, Randstad in the Netherlands, and the Northeastern Seaboard in the United States.

A metropolitan area or metro is a region consisting of a densely populated urban agglomeration and its surrounding territories which share industries, commercial areas, transport network, infrastructure and housing. A metropolitan area usually comprises multiple principal cities, jurisdictions and municipalities: neighborhoods, townships, boroughs, cities, towns, exurbs, suburbs, counties, districts and even states and nations in areas like the eurodistricts. As social, economic and political institutions have changed, metropolitan areas have become key economic and political regions.

In the United States, metropolitan areas are delineated around the core of a core based statistical area, which is defined as an urban area and includes central and outlying counties. In other countries metropolitan areas are sometimes anchored by one central city such as the Paris metropolitan area (Paris). In other cases, metropolitan areas contain multiple centers of equal or close to equal importance, especially in the United States; for example, the Dallas–Fort Worth metropolitan area has eight principal cities. The Islamabad–Rawalpindi metropolitan area in Pakistan, the Rhine-Ruhr in Germany, and the Randstad in The Netherlands are other examples.