Hi Mary,
They mean more or less the same thing. Although sometimes the pauper in question may have been interred in a family plot, if one existed, at the expense of the parochial board. This of course would save space in the common ground. There is much evidence in the Cambusnethan records that this did happen. It just meant that the parish paid for the coffin, transport to the place of burial and for the opening of the ground.
The parochial board always had several areas throughout the burial ground that were set apart for paupers. Usually but not in every case, they were areas that due to bad drainage, solid rock - whinstone etc; parishioners didn't want. (The parochial board had a duty towards all the poor of the parish, not just those who worshiped in the parish church but to all denominations).
It will probably be impossible to pinpoint a grave in any surviving piece of common ground into which a particular pauper has been interred. No grave markings of any kind plus the planting of trees and flowerbeds over the years would make the area unrecognisable now.
Lodger.