A backup repository contains three different file types:
.vbk: These files are the full VM image backups.vibor.vrb: These files are used to store incremental changes to VM images.vbm: These files are the backup metadata files that contain information on the backup job, VMs in the backup, restore points, and so on
This modular approach means that you can copy a backup from one repository to another and still keep the backup job information associated with it. Just as VMs are portable in a virtualized environment, Veeam Backup & Replication backup jobs are portable as well. In fact, you can copy them manually between repositories if so desired.