It only means that file was changed since it was last scanned. It's nothing to worry about. By the way, Goolge is your friend, really, they love you. I searched "avg result/infection change" and the first 5 links were answers to this same question.
Yeah there would. Even people that use search would need help because a lot do not know how to search. What I mean by that is using the 'deep searching' parts of Google or other search engines.