When the delete function is pressed, the file is usually preserved on the hard disk, only the pointer that creates the link to the file is deleted, thus preventing access to the file. To delete the file properly and make it unreadable, there are file shredders, File Shredder.
The control character (DEL) from the 7-bit code is used to delete or overwrite incorrect or unwanted characters. DEL is also available as a key (Del) on the keyboard. Furthermore, DEL is also used as a fill character that can be added to a message without changing its meaning. Also used as a pause character in transmission gaps.