1   erase

On my system, the backspace key, as I presses it, sends out ^? or 0x7F, also known as Delete character. Another common is ^H or 0x08 or Backspace. Whichever it is, in the terminal or console, you expect to see one character being deleted.

To check the current key, simply type:

$ stty -a
speed 38400 baud; rows 25; columns 118; line = 0;
[snip]; erase = ^?; [snip]; werase = ^W; [snip]

You can see erase currently is set to ^?. To change it to something else, say x, yes it doesn’t make sense, but it’s just and example:

$ stty erase x

Now if you type x, it deletes one character; and if you press backspace, the terminal echos out ^? literally as your eyes see. To set back, you can either do:

$ stty erase <you hit backspace>
# or simply with two literal charcters "^" and "?"
$ stty erase ^?
# or if you use Bash
$ stty erase $'\x7f'

If your backspace sends out ^H, then use $'\x08' or literal ^H.

2   werase

werase is word erase key, on my sytem, it’s ^W or 0x17 or End of Transmission Block when I press Ctrl+W. I could change it to tab if I want to:

$ stty werase $'\x09'

3   Other special characters?

You can change more than these two, such as Ctrl+C of intr or Ctrl+Z of eof, see:

info coreutils 'stty invocation' 'Characters'