It’s simple. A domain registration has the sole function of specifying DNS servers. In order to find services provided for your domain name, a number called an IP address is required. DNS servers map names to these numbers. The DNS servers have entries like:
BaileysKarate.com -> 126.96.36.199 www.BaileysKarate.com -> 188.8.131.52
They give out this information when asked.
DNS servers are controlled by hosting companies so that they can provide services on IP addresses they chose. Customers register domains and set the DNS servers as instructed by their hosting company. When they switch hosting companies, they can modify their registration to use the DNS servers from the new company. And that is really all there is to that.
To change hosting providers, all you have to do is log in to your account with us or where ever you bought your domain name and change the DNS servers it is set to use. Nothing needs to get transferred. It’s just a settings change which is very easy to do.
Of course this assumes that you have access to and control your domain registration. Sometimes hosting companies subsume control to make it much harder for their clients to leave them. That’s a subject for a different post. At Deerfield Hosting, we always register domains in our customers’ name. If you paid for your domain registration, you should control it!