Flemish or Belgian Dutch (Belgisch-Nederlands [ˈbɛɫʝis ˈneːdərlɑnts], or Vlaams) is the Dutch language as spoken in Flanders, the northern part of Belgium, be it standard (as used in schools, government and the media) or informal (as used in daily speech, "tussentaal" [ˈtʏsə(n)ˌtaːɫ]). There are four principal Dutch dialects in Flanders: Brabantian, East Flemish, West Flemish, and Limburgish. The latter two are sometimes considered separate languages.
Linguistically, 'Flemish' is sometimes used as a term for the language of the former County of Flanders, especially West Flemish. However, as a result of political emancipation of the Dutch-speaking part of Belgium, the combined culture of that region (which consists of West Flanders, East Flanders, Flemish Brabant, Antwerp, Limburg and Brussels) has come to be known as 'Flemish' and so sometimes are the four dialects or the common intermediate language. Despite the name, Brabantian and in particular its Antwerp dialect is the dominant contributor to the Belgian tussentaal. Using it for the official language in Flanders is misleading: the only official language in Flanders is Dutch. (Wikipedia)