Central business district
A central business district (CBD) is the commercial and business centre of a city. In larger cities, the often call it the city's "financial district". It is often located at the center of the city but not always.
The way a CBD looks is almost depending on the city's history. Cities with strong laws that keep history usually have maximum building height restrictions to retain the character of the history and culture. This is quite common for European cities such as Paris or Vienna. In cities in the New World a single central area or downtown will often contain most of the region's tallest buildings and act both as the CBD and the commercial and cultural city centre. Increasing urbanization in the 21st century have developed megacities, particularly in Asia, that will often have multiple CBDs scattered across the urban area.