- It is the name of one of the three regions constituting the Belgian federation (the others are Flanders and Wallonia).
- The Brussels Capital Region consists of only one administrative district (the Brussels Capital District) in which there are 19 municipalities (See: List of municipalities of the Brussels Capital Region). On January 1st, 2003, the city had a population of 992,041 for 161.382 km² which gives a population density of 6,309 inhabitants per km².
- As mentioned in point 2 Brussels is also one of the nineteen municipalities located in the Brussels Capital Region and District. The municipality comprises the city of Brussels proper and the towns of Haren (Dutch) or Haeren (French), Laken (Dutch) or Laeken (French) and Neder-Over-Heembeek (Dutch and French). On January 1st, 2000 Brussels municipality (Bruxelles-ville) had a total population of 133,859 (66,380 males and 67,479 females). The total area is 33.39 km² which gives a population density of 4,008.95 inhabitants per km².
- As mentioned in point 3 Brussels is also the main city within the Brussels municipality.
- The three main institutions of the European Union, the European Commission, the Council of the European Union and the prepatory and committee functionaly of the European Parliament (the plenary sessions are held in Strasbourg), have their headquarters in Brussels, making it the de facto capital of the European Union. This leads to a fifth meaning, especially in British English, where the city is used as a metonym for some aspects of the Union. "Brussels is considering banning raunchy TV images"
The language frontier divides Belgium into a northern, Dutch-speaking, region and a southern, French-speaking, region. The Brussels region is officially bilingual. The area, which is geographically situated in the south of Flanders, was mostly Dutch-speaking until the end of the 19th century. Over the years, however, more and more French-speaking civil servants and businessmen settled in Brussels and today the majority of its population speaks French.