Graveyards vs. Cemeteries

   All my years of being a tombstone aficionado, and I had to find out the difference on a historical tour.  A graveyard is on the grounds of a church, i.e. consecrated ground, and a cemetery is public ground.  Did you already know that?  Am I the only human left who didn't know?  Ah well, wouldn't be the first time I was caught up short by something I should definitely know.