When I set up a droplet I was "lazy" with naming. Now my hostname is "First.com". And there are two websites on the server (NGINX).

I want to change hostname from "First.com" to Production. But I am slightly lost since two FQDN are pointing to the same machine.

Should I do as following:

change in /etc/hostname to Production (as from now it was First.com)
(* this one for me is logical *)

change in /etc/hosts:
127.0.1.1 SITEA.COM
127.0.1.1 SITEB.COM
(now it was 127.0.1.1 First.com)

I am especially lost by this 127.0.1.1 loop-back.

Or should I do:
(real-ip) SITEA.COM
(real-ip) SITEB.COM

Or should I just
127.0.1.1 Production

Matej