The folder is used to save certain deleted files. (like the Recycle Bin).
Let me provide some background info about this issue:
(1) When you delete a file / folder on DriveHQ, the file is indeed deleted. There is no way to recover the file / folder.
(2) A lot of people use DriveHQ FileManager for backing up files. Some of them manually drag and drop files / folders from their local PC to DriveHQ Online Storage; some people use FileManager's Folder Synchronization feature to automatically backup data.
(3) DriveHQ Online Backup is designed for data backup, it is "set and forget", more robust, can backup any size folders / files. It can also keep multiple versions, so in case of accidental overwrite or deletion, your data on DriveHQ will still be safe.
(4) DriveHQ FileManager's folder synchronization feature is designed to sync a small folder with less than 3000 files and sub-folders in it. Also, dependent on the data size, folder synchronization could also take a long time to finish.
Now it is very important to note: Folder Synchronization is not the same as Backup. When you delete a file on your local PC, the sync-ed file on DriveHQ will also be deleted. In the past, we had a few users who deleted files in a sync-ed folder without realizing that files on DriveHQ server will also be deleted. For better protection, now DriveHQ FileManager moves the deleted files to the SyncCache folder in this scenario. You can feel free to delete the folder or files in it.