The Domain Name System is a useful tool.
For decades, humans had to live with the inconvenience of remembering phone numbers in order to use telecommunications products. With the advent of the internet, we thought it would be nice to automate this a bit, so you could just remember a word, like "huge fucking douchebags" in order to visit the site:
And indeed, this is much easier to remember than "126.96.36.199". It also allowed web site administrators host more than one site on a single IP address, by looking at the requested URL and the domain name within it. Blah blah blah boring technical details.
Ultimately, all it is is a convenient phone book. Like the contacts list on your smartphone, the names are only bookmarks.
This is why I find it so amusing that the anti-piracy kops are so focused on getting at domain names and their owners. In the linked article, the RIAA is trying to get a court order to find out who the registered owners of some piracy associated domain names are, with the unstated assumption that they are the "guilty" parties.
As you can see, by this logic, it is the RIAA who own the domain name "hugefuckingdouchebags.com", when in fact, it's me.