Just to clarify

I see many people posting their hands and sometimes at the top it will say 1/2 NL at Party. The 1/2 are small and big blinds respectively, I'm almost sure(correct me if I'm wrong). But what is the difference if someone's hand history shows 200NL. Is that what the buy in for that game is? And typically what are the blinds for that buy in or is that irrelevant? Is it best to focus on the buy in or the blind amounts?