Belgian Dutch — Flemish — is spoken by roughly 6.5 million people in the northern regions of Belgium (Flanders and Brussels). While mutually intelligible with Netherlandic Dutch, Flemish has distinct pronunciation, vocabulary, and cultural identity. Flemish speakers do not call themselves Dutch (Nederlands refers to the language but not the nationality) — they are Belgian and proud of a distinct Flemish identity, separate both from the French-speaking Walloons and from the Dutch of the Netherlands.
Cultural differences between Flemish and Dutch culture: Flemish culture tends to be slightly more formal, more Catholic (historically), more conservative in social rituals, and warmer in interpersonal style compared to the Netherlands. The Vlaamse Beweging (Flemish Movement) for greater autonomy or independence from Belgium is politically significant. Belgian food culture is arguably richer — Belgium is famous for beer (Belgisch bier), chocolate (chocolade), waffles (wafels), and frites (frietjes — the Belgians invented what the world calls “French fries”).
Flemish vocabulary to know: goesting (desire/feel like — vs. Dutch zin), plezant (pleasant/fun — vs. Dutch leuk), proper (clean/nice — vs. Dutch schoon/netjes), kot (student room), kuisen (to clean), smijten (to throw — vs. Dutch gooien), allez (come on! — from French). Flemish media — the public broadcaster VRT and commercial channels — broadcasts in excellent, clear Flemish Dutch and is freely accessible online.