Continuing the house analogy — imagine the house (server) your domain lives in as having an absolute street address, and when you move in, you put a sign over your door with your domain name, like a quaint wooden carved sign saying “Elaine Miller”.
Instead of your house address reading 1234 anywhere st, Vancouver, Canada, your IP address might read something like 220.127.116.11.
When you make a contract with a landlord (host) to rent a house for your household or business (server space for your website), you move in your stuff, product, or furniture (website files and online applications) and the landlord sets you up with some utilities, and you hang your little sign up.
But how do they find you?
Here’s the complex part. When I type your name (domain name) into the address bar of a browser, the browser learns that Elaine Miller (elainemiller.com) is located at 18.104.22.168, and knocks on the door of the server at that address to ask for the files you sent it for.
How does it find out what your IP address is? It asks the official town gossip — a “domain name server”.
“Say”, your browser says “Where is Elaine Miller Dot Com living nowadays?”
“Oh, Elaine Miller Dot Com, I know of her, she’s over at 22.214.171.124.
The official town gossips (domain name servers) all know each other, and all talk endlessly. When you move, or start a new household (a website with your own domain name), you tell your domain name registrar which particular domain name server is the one who is allowed to know your whereabouts most intimately. This is usually the DNS your webhost runs or accesses. You know, the gossip for your particular little village.
Since the Domain Name servers all gossip to each other, it tells two friends, then they tell two friends, and so on and so on. It’s called propagation.
“Did you hear? Elaine Miller Dot Com just moved to 126.96.36.199.”
Since there’s a lot of Domain Name servers, this process takes a while before every one of ’em knows where you are. (24 – 72 hours) If, in the meanwhile, someone’s browser asks for your domain’s address, the nameserver will be confused, and will not know where to send them, and the user will get an error message.
Domain Name Registrars
Registrars are like little tyrants, to whom you must apply to rent your domain name on a yearly basis. Each domain name + extension combo (name.com, othername.org, othername.net) is unique.
Registrars keep records of who owns (rents) which name, and part of the record (Besides your name and mailing address and phone number and such) is the name of the domain name server which is assigned to keep track of your number (IP) address.