The first, second and third prizes in the semi-finals are distributed in proportion (of course, there are also those without prizes), which is a provincial prize.
You must win the first prize (that is, the top few in the province) before you can enter the provincial team and participate in the winter camp of mathematics competition. The winter camp is the national finals, including the selection of the national team. Only the winter camp has a national prize, and everyone has it. The first, second and third prizes correspond to gold, silver and bronze medals.
Some national gold medals will stay for national team training, and then the national team will be selected to participate in the International Mathematical Olympiad (IMO), which is the highest level of mathematical competition.