The difference between a graveyard and a cemetery is that the former is an actual place, whereas the latter is a plot of land that is not actually a cemetery. It is a place of rest and it is a place to be cared for.
What you really need to know, though, is that there are people who are buried there, so the cemetery is actually a place of rest, and it is a place of burial. This is an important point for us, too.