Meaning that if i navigate trought my website, the URL is always updated.
When i get one of those from domain websites that have no direct contact with my hosting service, they work with na iframe.
Meaning that, while i navigate trought the site, i’ll always get
On the side of web host: add domain name to existing or new web hosting account
On the side of the domain name registrar: change nameservers to the ones which web host provides for you (or A record).
Upload content.
Wait for 48-72 hours
Is the question about main page of the web site you are getting at? in your first example I suppose you have web application installed and apache redirects you to the main page of web application.
Remember your domain name will never work as web site until you link your web site and hosting between each other.
On your account on the domain name registrar there is an option to change nameservers for your domain name. Your web host must provide you nameservers.
That is easy and if you ask for a help both domain name registrar and web hosting will help you
What you really want to be doing is pointing the name servers of your domain name, to those of your chosen web hosting company (they should send you them in a welcome email), that way you’ll avoid the frames redirect.