WordPress Multi site Map Domains

Question

I am try to use full domain instead of sub domains for multi network WordPress site.

When I check the WordPress documentation , I found following thing.

Make sure all the domains you want to use are already mapped to your DNS server. The additional domains should be parked upon the master domain.

1. What it means that "Make sure all the domains you want to use are already mapped to your DNS Server"?

2. What it means that "additional domains should be parked upon the master domain"?

Answer 1

It means that all domains have to be pointing to exactly the same server and exactly the same directory on that server.

All domains should be served by the same code, so all of them have to point to the same code...