How to link 2 domains for one site without a redirect?

Question

Domain Name System

Good afternoon, please tell me, in general, is it possible to link two different domains for one site, only so that it would not be a redirect from one to another, but directly accessible from both addresses. And will it be possible to do this without a dedicated IP (on a shared)?
So far, from the sane, I found only this. But the logic of the manual is not entirely clear to me, because in the database for wp, the domain name is hard-coded.
Thank you.

Answer 1

If your shared hosting allows you to edit DNS resource records, use CNAME.
site2.com | CNAME | site1.ru

Answer 2

Add the same IP in the second domain
Do not forget that in the
nginx settings you need to add
either apache
Well, or add an alias in the administrative panel