[OT] What is DEL for?

[Marco Cimarosti]

What is the function of ASCII control code 0x7F (DEL) in text interchange?

Particularly, what effect or interpretation might it have in communication
protocols, terminal protocols and, especially, inside text files?

My interest is about the function of this character in *contemporary*
platforms and software, although I wouldn't dislike historical information,
as far as it is clearly flagged as such.

Thanks for any info.

Ciao.
_ Marco