I can never get the [censored] that that website is trying to tell me.
They do write in their own unique way
But what they are saying are that the classical heroes are like knights in shining armor, or super heroes like Superman that only do good things exactly all the time.
And then anti-heroes are like lesser heroes. They have good intentions, they want to do good, but may fail alot or turn to evil actions to have a good outcome. Think the movie Kickass. He's an Anti-Hero Type 1, most likely. He only has good intentions, to save people like the classical heroes do, but he svcks at it, he's just a teenager with no fighting experience. Then that Batman wannabe comes into the picture - He's probably an Anti-Hero Type 4. Good intentions, he wants a better world but recongnize that the world is full of scum and always will be, and he ruthlessly kills these scum. He's a likeable character, he's got good intentions, but he's out on a revenge, on a killing spree of bad guys. He fights evil in evil ways.
So do you see how that Type 1 Anti-Hero is a good hero that is mostly good but not 100% good, and a Type 5 Anti-Hero is a good hero that is mostly evil but not 100% evil. The higher the number of the type they are, the worse of an hero they are while they are not crossing the line of becoming a Villain.
If you don't play characters that are either a Hero (goody two-shoes that only does good decisions all the time, never getting negative karma) or Anti-Hero (what I just described, good intentions but sometimes you do something less good because the outcome might be better in the end or you just need money), then you are probably a Villain (or in Fallout - Stupid Evil) or Anti-Villain (like the Anti-Hero, but reversed - you do evil things, you are greedy and all that, but sometimes you just do something good or wants to be a better villain that someone, and through greed, help the good side)