When Trash Bin is emptied, what we deleted is not actually the file. It is just the access of the file from the system that you lose. The space occupied by deleted files will be marks as “available to refuse” so that the deleted files remain physically intact until they are overwritten by other files. And these files will be deleted only when they are overwritten by other files. We have to stop using Mac immediately if we want to prevent overwriting and to recover deleted data from Mac trash.