Cooked mode (or ICANON for later drivers) did the ERASE, KILL, (and later) WERASE. The later TCSH, KSH, BRL 5R2 version of the (with editing turned on) Bourne Shell, etc... ran the shell in raw (-icanon) mode to do fancier editing including moving the cursor back over already entered text and to insert/delete at the cursor.