noninteractive
This is the anti-frontend. It never interacts with you at all, and makes the default answers be used for all questions.
It might mail error messages to root, but that's it; otherwise it is completely silent and unobtrusive, a perfect
frontend for automatic installs. If you are using this front-end, and require non-default answers to questions, you
will need to preseed the debconf database; see the section below on Unattended Package Installation for more details.
From
man 7 debconf
: