When you copy a document vault, a copy of the original vault will be displayed in both M-Files and on the computer's hard drive, in the same way as when creating a new document vault (see Document Vault Overview). You can also just copy parts of the document vault and select these under Data to copy.
For example, if you have found the structure of an old document vault useful and want to copy it to a new vault without the actual content, you can easily do this by clicking the Structure Only button. This way, you can utilize, for instance, the Demo Vault included in the M-Files installation.