newbie: iptables gone, what about apache?

[Anthony Griffiths]

I've installed nginx-1.12.2 on a centos 6.9 server and got it running
and streaming live video. I compiled it from source using the
instructions here:
https://www.nginx.com/resources/admin-guide/installing-nginx-open-source/
My main aim is to get nginx streaming live video to phones but more of
that later...
After the install I noticed I no longer have /etc/sysconfig/iptables.
What did nginx replace it with?
Also, if I have apache and some websites already set up on the centos
6 machine how does nginx get along with that? (if it serves it's own
pages at /usr/local/nginx/html) Thanks for any advice.