oh never mind you're 9 you might genuinely not know, basically it's a list of rules governments  have to follow to respect basic human rights, with much of it pertaining to conduct in war, but not exclusively being about it. one being you can't use the medical red cross symbol on things that aren't medical, because you're not allowed to attack medical staff unless they are firing at you, and for some reason the Red Cross organization enforces this even upon videogames