Central business district

A central business district (CBD) is the commercial and business center of a city. It contains offices and shops. In larger cities, it may be called the city's "financial district". It is often located in the city center but not always. 
Examples of CBDs include Midtown Manhattan which is the largest central business district in New York City or the Xinyi Planned Area in Taipei
The city's history influences the way a CBD looks. Some cities have strong laws that forbid tall buildings, 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 metropolitan area's tallest buildings and act both as the CBD and the commercial and cultural city centre. Increasing urbanization in the 21st century has created megacities, particularly in Asia, that will often have multiple CBDs scattered across the urban area.