This part is straightforward:
Understanding this label provides a window into the ISO's technical details and intended use, revealing the specific version of Windows it contains. cpba-x64fre-en-us-dv9
If you see this drive letter taking up space in your file directory, it can be safely removed without impacting system performance. For Virtual Mounted Disk Images Open or Windows Explorer. in an ISO filename
If you have encountered the alphanumeric string CPBA-X64FRE-EN-US-DV9 (or similar variants starting with CCCOMA/CENA) on a DVD label, in an ISO filename, or as a mounted drive in Windows Explorer, you are looking at official . cpba-x64fre-en-us-dv9
Short for "Free" (or Retail/Final Release). In Microsoft development terms, a "Free" build is optimized for performance and stripped of heavy debugging code, unlike a "CHK" (Checked) build used by developers.