I can buy a domain name from GoDaddy or similar, and then I get to associate it with some IP address I have control over (e.g. a web server).  But when I buy a domain name, what happens on the registrar's end?  More specifically, what aspect of the registrar's infrastructure is updated to reflect my ownership of a domain name I purchase?
When I buy a domain name, what am I actually getting?
domains;dns;domain registration;domain registrar;ownership