One of the most significant innovations introduced in the version 5 lifecycle, and perfected by 5.1.12, is the folder. In the past, creating a "clone" meant the destination drive was erased completely. If you wanted to update your backup, CCC would delete the old backup and replace it with the new data.
Musicians and video editors love the "Cheese Grater" Mac Pro running High Sierra or Mojave. CCC 5.1.12 is the last version that reliably clones PCIe NVMe drives on these old PCIe 2.0 slots without kext conflicts. Carbon Copy Cloner 5.1.12