Housing in the context of "Ministry of Public Works and Transport (Spain)"

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 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.

The term built environment refers to human-made conditions and is often used in architecture, landscape architecture, urban planning, public health, sociology, and anthropology, among others. These curated spaces provide the setting for human activity and were created to fulfill human desires and needs. The term can refer to a plethora of components including the traditionally associated buildings, cities, public infrastructure, transportation, open space, as well as more conceptual components like farmlands, dammed rivers, wildlife management, and even domesticated animals.

The built environment is made up of physical features. However, when studied, the built environment often highlights the connection between physical space and social consequences. It impacts the environment and how society physically maneuvers and functions, as well as less tangible aspects of society such as socioeconomic inequity and health. Various aspects of the built environment contribute to scholarship on housing and segregation, physical activity, food access, climate change, and environmental racism.

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.

Informal housing or informal settlement can include any form of housing, shelter, or settlement (or lack thereof) which is illegal, falls outside of government control or regulation, or is not afforded protection by the state. As such, the informal housing industry is part of the informal sector.

To have informal housing status is to exist in "a state of deregulation, one where the ownership, use, and purpose of land cannot be fixed and mapped according to any prescribed set of regulations or the law". While there is no global unified law of property-ownership, the informal occupant or community will typically lack security of tenure and, with this, ready or reliable access to civic amenities (potable water, electricity and gas supply, road creation and maintenance, emergency services, sanitation and waste collection). Due to the informal nature of occupancy, the state will typically be unable to extract rent or land taxes.

Homelessness, also known as houselessness or being unhoused or unsheltered, is the condition of lacking stable, safe, and functional housing. It includes living on the streets, moving between temporary accommodation with family or friends, living in boarding houses with no security of tenure, and people who leave their homes because of civil conflict and are refugees within their country.

The legal status of homeless people varies from place to place. Homeless enumeration studies conducted by the government of the United States also include people who sleep in a public or private place that is not designed for use as a regular sleeping accommodation for human beings. Homelessness and poverty are interrelated. There is no standardized method for counting homeless individuals and identifying their needs; consequently, most cities only have estimated figures for their homeless populations.

Employment is a relationship between two parties regulating the provision of paid labour services. Usually based on a contract, one party, the employer, which might be a corporation, a not-for-profit organization, a co-operative, or any other entity, pays the other, the employee, in return for carrying out assigned work. Employees work in return for wages, which can be paid on the basis of an hourly rate, by piecework or an annual salary, depending on the type of work an employee does, the prevailing conditions of the sector and the bargaining power between the parties. Employees in some sectors may receive gratuities, bonus payments or stock options. In some types of employment, employees may receive benefits in addition to payment. Benefits may include health insurance, housing, and disability insurance. Employment is typically governed by employment laws, organization or legal contracts.

A cost-of-living crisis is a socioeconomic situation or period of high inflation where nominal wages have stagnated while there is a sharp increase in the cost of basic goods, such as food, housing, and energy. As a result, living standards are squeezed to the point that people cannot afford the standard of living that they were previously accustomed to. Public health is threatened. The population becomes 'poorer' than it used to be in real terms. This is in contrast to a situation in which wages are rising to meet the rate of inflation and workers' standard of living remains unchanged.

During the 2020s, a cost-of-living crisis impacted many countries around the world amid global inflation. In February 2023, 3 out of 4 consumers globally were worried about the rising cost of everyday expenses. The Big Issue defines a cost of living crisis as "a situation in which the cost of everyday essentials like groceries and bills are rising faster than average household incomes". Change in average real incomes can be measured by real GNI per capita change.