Are Dutch and Belgians of the same nationality or descent? Why do many Belgians have the words "Fan" or "Van der" in their names?

Some people in Belgium speak French; Some people live in Flemish-speaking areas and speak Flemish, which is actually Dutch, but with an accent; A few people also speak German. So Belgium has a trilingual government. . . ⊙﹏⊙b bay. . This is a chaotic country.

Fan is van, which is equivalent to English of; Yes, it is, which is equivalent to English.

Dutch surnames also carry van or de. Ancient Dutch civilians had no surnames. Some Dutch people told me that the French (like Napoleon) occupied the Netherlands and forced the Dutch to take their surname. The Dutch are unhappy and take many strange surnames at will. . . Van and de are both right. Some Dutch people's surnames mean fishermen and butchers, which is very funny. . .

The Flemish Belgians may be descended from the Dutch, otherwise they would not be named in the Dutch way. However, from the outside, the Dutch look much better than the Belgians, and they may be mixed-blood descendants of the Belgians. . .