Infrastructure in the context of Polycentric metropolitan area

An urban area is a human settlement with a high population density and an infrastructure of built environment. 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 BCEled 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.

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.

A civilization (also spelled civilisation in British English) 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).

Civilizations are organized around densely populated settlements, divided into more or less rigid hierarchical social classes of division of labour, often with a ruling elite and subordinate urban and rural populations, which engage in intensive agriculture, mining, small-scale manufacture and trade. Civilization concentrates power, extending human control over the rest of nature, including over other human beings. Civilizations are characterized by elaborate agriculture, architecture, infrastructure, technological advancement, currency, taxation, regulation, and specialization of labour.

A slum is a derogatory term for a highly populated urban residential area consisting of densely packed housing units of weak build quality and often associated with poverty. The infrastructure in slums is often deteriorated or incomplete, and they are primarily inhabited by impoverished people.

Although slums are usually located in urban areas, they can be located in suburban areas where housing quality is low and living conditions are poor. Slum residences vary from shanty houses to professionally built dwellings which, because of poor-quality construction or lack of basic maintenance, have deteriorated. While slums differ in size and other characteristics, most lack reliable sanitation services, supply of clean water, reliable electricity, law enforcement, and other basic services. The United Nations defines slums as ".... informal settlements lacking one or more of the following conditions: access to improved water, access to improved sanitation, sufficient living area, housing durability, and security of tenure."

Transport (in British English) or transportation (in American English) is the intentional movement of humans, animals, and goods from one location to another. Modes of transport include air, land (rail and road), water, cable, pipelines, and space. The field can be divided into infrastructure, vehicles, and operations. Transport enables human trade, which is essential for the development of civilizations.

Transport infrastructure consists of fixed installations, including roads, railways, airways, waterways, canals, and pipelines, as well as terminals such as airports, railway stations, bus stations, warehouses, trucking terminals, refueling depots (including fuel docks and fuel stations), and seaports. Terminals may be used both for the interchange of passengers and cargo and for maintenance.

A public utility company (usually just utility) is an organization that maintains the infrastructure for a public service (often also providing a service using that infrastructure). Public utilities are subject to forms of public control and regulation ranging from local community-based groups to statewide government monopolies.

Public utilities are meant to supply goods and services that are considered essential; water, gas, electricity, telephone, waste disposal, and other communication systems represent much of the public utility market. The transmission lines used in the transportation of electricity, or natural gas pipelines, have natural monopoly characteristics. A monopoly can occur when it finds the best way to minimize its costs through economies of scale to the point where other companies cannot compete with it. If the infrastructure already exists in a given area, minimal benefit is gained through competing. In other words, these industries are characterized by economies of scale in production. Though it can be mentioned that these natural monopolies are handled or watched by a public utilities commission, or an institution that represents the government.

Urban planning (also called city planning or town planning in some contexts) is the process of developing and designing land use and the built environment, including air, water, and the infrastructure passing into and out of urban areas, such as transportation, communications, and distribution networks, and their accessibility. Traditionally, urban planning followed a top-down approach in master planning the physical layout of human settlements. The primary concern was the public welfare, which included considerations of efficiency, sanitation, protection and use of the environment, as well as taking account of effects of the master plans on the social and economic activities. Over time, urban planning has adopted a focus on the social and environmental "bottom lines" that focuses on using planning as a tool to improve the health and well-being of people and maintain sustainability standards. In the early 21st century, urban planning experts such as Jane Jacobs called on urban planners to take resident experiences and needs more into consideration.

Urban planning answers questions about how people will live, work, and play in a given area and thus, guides orderly development in urban, suburban and rural areas. Although predominantly concerned with the planning of settlements and communities, urban planners are also responsible for planning the efficient transportation of goods, resources, people, and waste; the distribution of basic necessities such as water and electricity; a sense of inclusion and opportunity for people of all kinds, culture and needs; economic growth or business development; improving health and conserving areas of natural environmental significance that actively contributes to reduction in CO₂ emissions as well as protecting heritage structures and built environments. Since most urban planning teams consist of highly educated individuals that work for city governments, recent debates focus on how to involve more community members in city planning processes.

A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task, and proto-typically refers to solid hand-operated non-biological objects with a single broad purpose that lack multiple functions, unlike machines or computers. Although human beings are proportionally most active in using and making tools in the animal kingdom, as use of stone tools dates back hundreds of millennia, and also in using tools to make other tools, many animals have demonstrated tool use in both instances.

Early human tools, made of such materials as stone, bone, and wood, were used for the preparation of food, hunting, the manufacture of weapons, and the working of materials to produce clothing and useful artifacts and crafts such as pottery, along with the construction of housing, businesses, infrastructure, and transportation. The development of metalworking made additional types of tools possible. Harnessing energy sources, such as animal power, wind, or steam, allowed increasingly complex tools to produce an even larger range of items, with the Industrial Revolution marking an inflection point in the use of tools. The introduction of widespread automation in the 19th and 20th centuries allowed tools to operate with minimal human supervision, further increasing the productivity of human labor.

Construction is the process involved in delivering buildings, infrastructure, industrial facilities, and associated activities through to the end of their life. It typically starts with planning, financing, and design that continues until the asset is built and ready for use. Construction also covers repairs and maintenance work, any works to expand, extend and improve the asset, and its eventual demolition, dismantling or decommissioning.

The construction industry contributes significantly to many countries' gross domestic products (GDP). Global expenditure on construction activities was about $4 trillion in 2012. In 2022, expenditure on the construction industry exceeded $11 trillion a year, equivalent to about 13 percent of global GDP. This spending was forecasted to rise to around $14.8 trillion in 2030.

Public works are a broad category of infrastructure projects, financed and procured by a government body for recreational, employment, and health and safety uses in the greater community. They include public buildings (municipal buildings, schools, and hospitals), transport infrastructure (roads, railroads, bridges, pipelines, canals, ports, and airports), public spaces (public squares, parks, and beaches), public services (water supply and treatment, sewage treatment, electrical grid, and dams), environmental protection (drinking water protection, soil erosion reduction,wildlife habitat preservation, preservation and restoration of forests and wetlands) and other, usually long-term, physical assets and facilities. Though often interchangeable with public infrastructure and public capital, public works does not necessarily carry an economic component, thereby being a broader term. Construction may be undertaken either by directly employed labour or by a private operator.

Public works has been encouraged since antiquity. The Roman emperor Nero encouraged the construction of various infrastructure projects during widespread deflation.

Engineering is the practice of using natural science, mathematics, and the engineering design process to solve problems within technology, increase efficiency and productivity, and improve systems. The traditional disciplines of engineering are civil, mechanical, electrical, and chemical. The academic discipline of engineering encompasses a broad range of more specialized subfields, and each can have a more specific emphasis for applications of mathematics and science. In turn, modern engineering practice spans multiple fields of engineering, which include designing and improving infrastructure, machinery, vehicles, electronics, materials, and energy systems. For related terms, see glossary of engineering.

As a human endeavor, engineering has existed since ancient times, starting with the six classic simple machines. Examples of large-scale engineering projects from antiquity include impressive structures like the pyramids, elegant temples such as the Parthenon, and water conveyances like hulled watercraft, canals, and the Roman aqueduct. Early machines were powered by humans and animals, then later by wind. Machines of war were invented for siegecraft. In Europe, the scientific and industrial revolutions advanced engineering into a scientific profession and resulted in continuing technological improvements. The steam engine provided much greater power than animals, leading to mechanical propulsion for ships and railways. Further scientific advances resulted in the application of engineering to electrical, chemical, and aerospace requirements, plus the use of new materials for greater efficiencies.

A mode of transport is a method or way of travelling, or of transporting people or cargo. The different modes of transport include air, water, and land transport, which includes rails or railways, road and off-road transport. Other modes of transport also exist, including pipelines, cable transport, and space transport. Human-powered transport and animal-powered transport are sometimes regarded as distinct modes, but they may lie in other categories such as land or water transport.

In general, transportation refers to the moving of people, animals, and other goods from one place to another, and means of transport refers to the transport facilities used to carry people or cargo according to the chosen mode. Examples of the means of transport include automobile, airplane, ship, truck, and train. Each mode of transport has a fundamentally different set of technological solutions. Each mode has its own infrastructure, vehicles, transport operators and operations.

A government budget is a projection of the government's revenues and expenditure for a particular period, often referred to as a financial or fiscal year, which may or may not correspond with the calendar year. Government revenues mostly include taxes (e.g. inheritance tax, income tax, corporation tax, import taxes) while expenditures consist of government spending (e.g. healthcare, education, defense, infrastructure, social benefits). A government budget is prepared by the Central government or other political entity. In most parliamentary systems, the budget is presented to the legislature and often requires approval of the legislature. The government implements economic policy through this budget and realizes its program priorities. Once the budget is approved, the use of funds from individual chapters is in the hands of government ministries and other institutions. Revenues of the state budget consist mainly of taxes, customs duties, fees, and other revenues. State budget expenditures cover the activities of the state, which are either given by law or the constitution. The budget in itself does not appropriate funds for government programs, hence the need for additional legislative measures.

In economics, economic development (or economic and social development) is the process by which the economic well-being and quality of life of a nation, region, local community, or an individual are improved according to targeted goals and objectives.

The term has been used frequently in the 20th and 21st centuries, but the concept has existed in the West for far longer. "Modernization", "Globalization", and especially "Industrialization" are other terms often used while discussing economic development. Historically, economic development policies focused on industrialization and infrastructure; since the 1960s, it has increasingly focused on poverty reduction.

Sustainable transport is transportation sustainable in terms of their social and environmental impacts. Components for evaluating sustainability include the particular vehicles used; the source of energy; and the infrastructure used to accommodate the transport (streets and roads, railways, airways, waterways and canals). Transportation sustainability is largely being measured by transportation system effectiveness and efficiency as well as the environmental and climate impacts of the system. Transport systems have significant impacts on the environment. In 2018, it contributed to around 20% of global CO₂ emissions. Greenhouse gas emissions from transport are increasing at a faster rate than any other energy using sector. A 2023 study published in Journal of Transport Geography found that shared electric bicycle systems reduce urban transport-related carbon emissions by about 108–120 grams per kilometre, particularly in non-central urban areas and when powered by low-carbon electricity sources.Road transport is also a major contributor to local air pollution and smog.

Sustainable transport systems make a positive contribution to the environmental, social and economic sustainability of the communities they serve. Transport systems exist to provide social and economic connections, and people quickly take up the opportunities offered by increased mobility, with poor households benefiting greatly from low carbon transport options. The advantages of increased mobility need to be weighed against the environmental, social and economic costs that transport systems pose. Short-term activity often promotes incremental improvement in fuel efficiency and vehicle emissions controls while long-term goals include migrating transportation from fossil-based energy to other alternatives such as renewable energy and use of other renewable resources. The entire life cycle of transport systems is subject to sustainability measurement and optimization.