A city is an urban area that is differentiated from a town, village, or hamlet by size, population density, importance, or legal status. In most parts of the world, cities are generally substantial and nearly always have an urban core, but in the United States many incorporated areas which have a very modest population, or a suburban or even mostly rural character, are designated as cities. City can also be a synonym for "downtown" or a "city centre".

A city usually consists of residential, industrial and business areas together with administrative functions which may relate to a wider geographical area. A large share of a city's area is primarily taken up by housing, which is then supported by infrastructure such as roads, streets and often public transport routes such as a rapid transit system. Lakes and rivers may be the only undeveloped areas within the city. The study of cities is covered extensively in human geography.

"The city is a human habitat that allows people to form relations with others at various levels of intimacy while remaining entirely anonymous." (This definition was the subject of an exhibition at the Israeli pavilion at the 2000 Venice Biennale of architecture)