In general, a "revised" story is one which has undergone fairly substantial changes from when it was first posted. It's neither just better edited nor a brand new story, but one in which scenes have been added and/or expanded, plot changes have been introduced or explained, etc.
The main plot line is usually the same, but the author has decided to go further with the story, perhaps in order to address problems that were pointed out during the first posting, or just because they felt they could do a better job with the story by reworking it.
Kathy
