What is the difference between GC = Mark and GC = Punctuation Marks in General Unicode Categories?

I am having trouble understanding some concepts. The Unicode specification has a property called a general category .

OK I understood what each of the letters is (regular characters; GC=L), numbers (for example, numbers 0-9 and other characters with numerical values; GC=N) and delimiters (delimiters; GC=Z). But it’s very difficult to distinguish between characters ( GC=S), punctuation ( GC=P) and labels ( GC=M).

I looked through a list of them, but I could not find the conceptual difference. And the document doesn’t help me much. What is the difference between the two?