What makes some people succesful and others fail?

As FishBotThing said there are many factors so the path to success is different for everyone. However, one thing that separates the successful from those that fail is that the successful people also fail. They learn from those failures and never stop trying until they get it right. The unsuccessful people stop trying.

As a case in point, Henry Ford filed for bankruptcy twice before he got it right. Had he stopped trying after either bankruptcy he would have also been unsuccessful.