The country of Belgium is divided into three regions. Two of these regions, the Flemish Region or Flanders, and Walloon Region, or Wallonia, are each subdivided into five provinces. The third region, the Brussels-Capital Region, is not divided into provinces, as it was originally only a small part of a province itself.
Many of the provinces evolved from earlier duchies and counties of the same name and similar location, albeit often with significant shifts of boundaries. At the time of the creation of Belgium in 1830, only nine provinces existed, including the province of Brabant, which held the city of Brussels. In 1995, Brabant was split into three areas: Flemish Brabant, which became a part of the region of Flanders; Walloon Brabant, which became part of the region of Wallonia; and the Brussels-Capital Region, which became a third region. These divisions reflected political tensions between the French-speaking Walloons and the Dutch-speaking Flemish; the Brussels-Capital Region is officially bilingual.
The division into provinces is fixed by Article 5 of the Belgian Constitution. The provinces are subdivided into 43 administrative arrondissements, and further into 589 municipalities.
More information on the Wikipedia page [1]