Cheating versus hate speech, maybe?
Difference: Account closed because of "Abuse" versus "Fair Play"

Fair play is called The Red C, while abuse is called The Red Apple. And if you happen to know a friend that got the the red c then you say they drowned in the tub, but if they got the red Apple then you say that little snow white

Yes....since the site is basically 2 fold. Fair play is actually the playing of chess. Abuse is more of forum and posting activity.
Could be both, spamming the chat to distract the opponent

They might've cheated in a different game, but you'd still be rewarded your points if they got the red c in the time surrounding your match. In effect, it is the nullification of the member's activity within a certain period of time, in other words, whether he or she cheated im your match, by policy of chess.com that match was void. You were playing a ghost who drowned in the tub. Your points cannot be anchored to any solid account, they are afloat. The system...
The accounts of my last two opponents in a daily tournament were closed. One because of "violating the Fair Play Policy" (I got rating points awarded) and the other one because of "Abuse". What's the difference? Cheers!