An urban area [ a ] is a human settlement with a high population density and an infrastructure of built environment. This is the core of a metropolitan statistical area in the United States, if it contains a population of more than 50, Urban areas originate through urbanization , and researchers categorize them as cities, towns, conurbations or suburbs. In urbanism , the term "urban area" contrasts to rural areas such as villages and hamlets ; in urban sociology or urban anthropology , it often contrasts with natural environment.
The development of earlier predecessors of modern urban areas during the urban revolution of the 4th millennium BCE [ 3 ] led to the formation of human civilization and ultimately to modern urban planning , which along with other human activities such as exploitation of natural resources has led to a human impact on the environment.
In , million people or about 30 percent of the world's 2. By , it was 3. The change was driven by a combination of increased total population and increased percent of population living in urban areas.
Urban areas are created and further developed by the process of urbanization. They are measured for various purposes, including analyzing population density and urban sprawl. Urban areas are generally found in the United States , Canada , Brazil , Mexico , Argentina , Chile , Japan , Australia , and many other countries where the urbanization rate is high. Unlike an urban area, a metropolitan area includes not only the urban area, but also satellite cities plus intervening rural land that is socio-economically connected to the urban core city, typically by employment ties through commuting , with the urban core city being the primary labor market.
The concept of an "urban area" as used in economic statistics should not be confused with the concept of the "urban area" used in road safety statistics. This term was first created by Geographer Brian Manning. The last concept is also known as " built-up area in road safety ". According to the definition by the Office for National Statistics , "Built-up areas are defined as land which is 'irreversibly urban in character', meaning that they are characteristic of a town or city.
