What do cemeteries do with old bodies?

What do cemeteries do with old bodies? Thereafter, families can either pay to keep them (often on a rental basis) or the graves are recycled, with the most recent residents moved further into the ground or to another site, often a mass grave.

Thereafter, families can either pay to keep them (often on a rental basis) or the graves are recycled, with the most recent residents moved further into the ground or to another site, often a mass grave.