How to make a connection between domains?

Question

Domain name market

Good day everyone! I am very interested in how a subdomain is replaced with your own domain on many online services. I'll give an example to make it clear. For example, we register in the N system and get an address like our_login.domain.ru. In the settings, there is usually an option to change the domain to your own. We change the domain, buy it on reg.ru or transfer our own. At the same time, the resource is available and available under the old our_login.domain.ru. So this is how this change of our_login.domain.ru takes place. to my_domain.domain.ru. Where and what is registered in dns. How is it determined that this is my resource and that it is necessary to give content based on it?

Answer 1

When you have a domain, you will write in the DNS settings the IP of the server (or CHAME record) that the service will give you. The server, receiving a request for a domain, decides what to give to this address.

Answer 2

Specifically, Google gives two CNAME records for Blogger: www = ghs.google.com, and the second record is the hash code requested by ghs.google.com when broadcasting.