When you type in somedomain.com your internet service sends a message to a machine called a name server owned by your internet service and asks this machine “hey, where do I find the website for somedomain.com?”

If anyone using your internet provider has previously visited somedomain.com, The name server machine remembers this and says back to your internet browser, “it says here in my address book that somedomain.com is at this IP (internet protocol) address” which is a bunch of numbers and also “that IP address is controlled by so-and-so internet service provider.”  Your browser then sends a message to the names servers of so-and-so and asks “hey so-and-so, please point me to the machine with the IP address xxx” which it got from your name server.  So-and-so then points your browser to the machine with the web files for somedomain.com and voila.

If no one using your internet provider has ever visited somedomain.com, then your name server machine says “I’ve never heard of somedomain.com, let’s ask one of the root name servers.”  There are 13 root name servers in the world and these machines know the IP address of every single domain registered anywhere.   When I changed our name server records these changes had to be recorded in all of those 13 root name servers.  The root name server then sends back the info to your name server and your browser carries on as in the paragraph above.

:)