>>513476428If a situation says you are +X, it means if you and your opponent do the exact same move at the exact same time, yours will come out X frames faster than theirs. You are at "advantage".
The same is true in reverse: if a situation says you are -X, it means in that same situation, your move will come out X frames slower than theirs. You are at "disadvantage".
It is harder to fight from disadvantage, since your moves will be coming out slower than usual compared to your opponent's; you can try, but it'll probably be a little messy. If you are at advantage, you can press the issue more easily.
In Virtua Fighter, one of the core pillars of the VF Triangle is "guard beats strike." Outside of rare exceptions, if you attack into a block, you are ALMOST ALWAYS minus on block and thus at disadvantage. If you block an incoming attack, you are practically always at advantage and can seize the initiative from a better position.