Pit Bull question

Throughout my entire childhood, I was under the impression that "Pit Bull" meant "English Bull Terrier". Now I'm a grown-up on reddit and there's another dog that everyone says is a Pit Bull and it looks just like a staffy but... isn't? Are the other Pit Bulls still Pit Bulls? Is this an American thing? Are there other people who call English Bull Terriers "Pit Bulls" or was I mesled as a child?

Is this why Chance in the Homeward Bound Disney movie didn't look anything like the dog on the cover of the book? Like, he's still a Pit Bull but American now?