You may have heard of the recent Windows 10 update (now withdrawn) that was causing some users to lose their files. There is an analysis of the problem, reported here <https://www.theregister.co.uk/2018/10/10/microsoft_windows_deletion_bug/>. It was a consequence of a feature known as “Known Folder Redirection”, which it seems only exists because of the drive-letter limitations of Windows. The closest analogue might be Linux mount points or symlinks, only the Windows version is more complicated, in usual Microsoft fashion. One mystery is that the bug was reported by multiple testers months before release, yet it seems their reports were ignored.