For example if a folder is configured to use `/tmp/mapped` or `C:\mapped` as filesystem path and `/vfolder` as virtual path then SFTPGo users can access `/tmp/mapped` or `C:\mapped` via the `/vfolder` virtual path.
Folder quota limits can also be included inside the user quota but in this case the folder is considered "private" and sharing it with other users will break user quota calculation.
The calculation of the quota for a given user is obtained as the sum of the files contained in his home directory and those within each defined virtual folder.
If you remove a folder, from the data provider, any users relationships will be cleared up. If the deleted folder is included inside the user quota you need to do a user quota scan to update its quota. An orphan virtual folder will not be automatically deleted since if you add it again later then a quota scan is needed and it could be quite expensive, anyway you can easily list the orphan folders using the REST API and delete them if they are not needed anymore.