When you are done storing, sharing or viewing a file, it can be sent to the Trash where it can be permanently deleted. Once an item has been deleted from the Trash, it will never be recoverable.
Left click on the file or folder you wish to work with. Upon clicking, an option menu will appear. For files, you may restore, view, comment, download, view audit logs, and or delete. For files, you are given the choice to restore or delete only.