A central business district (CBD) is the commercial and often geographic heart of a city. In Australia, Bosnia & Herzegovina, China (especially Hong Kong), Ireland, Kenya, New Zealand, Singapore and South Africa, the phrase is commonly used, and is often colloquially abbreviated to "CBD".
The CBD is the central district of a city, usually typified by a concentration of retail and commercial buildings.
The term city centre (or city center) is similar to CBD in that both serve the same purpose for the city, and both are seen by a higher-than-usual urban density as well as the often having the tallest buildings in a city. City centre differs from downtown in that the latter can be geographically located anywhere in a city, while a city centre is generally located near the geographic heart of the city. London, United Kingdom, effectively has three city centres, the City of London, the medieval City of Westminster and Canary Wharf. Lucknow, India has three CBDs. The shape and type of a CBD or downtown almost always closely reflect the city's history. Cities with maximum building height restrictions often have a separate historic section quite apart from the financial and administrative district. In cities that grew up suddenly and more recently, such as those in the western half of North America, a single central area will often contain all the tallest buildings. It has been said that downtowns (as understood in North America) are therefore a separate phenomenon.
Central business districts usually have very small resident populations. For example, the population of the City of London declined from over 200,000 in 1700 to less than 10,000 today. In some instances, however (and particularly in large Australian cities), CBD populations are increasing as younger professional and business workers move into city centre apartments.
The land use in the central business district may follow the core frame model of urban structure. It is likely to have many of the following characteristics:
The alternative term city centre is used in Britain and Ireland, and also in some urban areas of British-influenced countries, such as the Commonwealth)and mainland China ().. In the United Kingdom, Australia, South Africa, Canada and New Zealand, the term is often just shortened to "city", as in "going to the city". This term is also used in the New York City area in the same manner, using the term the city to mean Manhattan. One exception is in London where "the City" specifically refers to the City of London financial district rather than to any other part of central London. In the UK, Australia, New Zealand, Ireland and many other parts of the world, it is often also referred to as "town" ("going (in)to town", "going up town", or "going down town").
In Paris the main business district is actually quite distant from the geographical centre of the city in La Defense, on the western edge of the boundries of the Paris commune (municipality). Brussels' historic centre is bounded by the inner ring road. However, the financial and administrative district is the Leopold Quarter. Montreal's historic core, Old Montreal, is no longer the financial district, which is now Downtown Montreal.
Some Francophone cities do use centre-ville to refer to the CBD. In Beirut, for example, although the CBD is officially called Beirut Central District, the Lebanese use the French term centre-ville.
In the United States, central business districts are often referred as "downtown" (even if there is no "uptown"). In most cities the downtown area will be home to the financial district, but usually contains entertainment and retail of some kind as well. The downtown areas of many cities, such as Chicago and Houston, are also home to large sports and convention venues. Historic sections of a central business district may be referred to as "old town", while decaying parts of the center city are commonly referred to as the "inner city". The term inner city is sometimes not used literally but rather evocatively, applying a negative connotation and referring paradoxically to peripheral areas blighted during a mass exodus of middle class residents.
Some cities in the United States and Canada, such as Vancouver, Minneapolis, and Dallas, Texas, have mixed use districts known as "uptown" in addition to the primary downtown core areas. In some cities, such as Charlotte, Chicago, and Oklahoma City, "uptown" is instead the historic name for a separate business center or neighborhood. Philadelphia and Wilmington, Delaware use the term center city instead of downtown for their central business districts. Some cities, such as Toronto, regard as many as four business districts as being central. Whereas in Los Angeles, the city core is simply known as downtown LA.
By broad definition, New York City's CBD comprises the whole southern half or third of Manhattan island. Narrow definitions include only a square mile or two (3-5 km²) of Midtown as central, with the lowest tenth of the island, including the Financial District, being a secondary business district rather than the central one. Similar narrow and broad definitions are applied to the Chicago's downtown high rise districts.