Domain Registration Process Behind the Scenes Question

Just had a quick question regarding the domain registration process.

As an owner of multiple domains, I just registered them without actually understanding the internal processes of what is going on behind the scenes

Can anyone chime in on what actually happens when you register a domain, say with Godaddy?

Is there some official regulatory database out there that a registrar such as Godaddy would send the domain registration information to?

What actually happens?

Also, what does a company like Facebook for instance do with their domain name? Do they have legal documents explaining that the domain is part of the company etc etc.. ?

Thanks..

Im without too much time but this is the organization behind domains:

http://www.icann.org/