To delete files, folders or Spaces, simply expand the item (desktop) or swipe it from left-to-right and click or tap the trash symbol.
When deleting a Space you will be met with the options to delete the Space locally, delete the Space from the server (if you have administrator rights in the Space) or to cancel the deletion operation.
When deleting a file or folder, the item will be moved to the respective trashcan of that Space. In order to delete files and folders permanently the Space’s trash must be emptied. The “Trash” section be found on the home screen.