JohnFulton.org

How does the Internet know to send our domain name (like http://www.johnfulton.org) to a specific physical computer (a host)?

The magic key is called a Domain Name Server (DNS). There are many DNSs scattered about the world. There are at least two at each interenet service provider and additional pairs of them at each major connection point in the Interent. Why do they exist in pairs? They are so crtitical that every effort is made to make sure that one is always running at each site. Hence, the idea of having two at each conneciton point.

The DNS contains a huge file that contains every domain name (like johnfulton.org) and associates with that name an internet address (called an IP(eye-pea) address). Every physical computer in the world that's connected to the internet has an IP address.

An IP address has the form of 4 numbers separated by dots. It's also called a "dotted internet address".

Just to prove that every computer connected to the Internet has an IP address, you can click on http://www.whatismyip.org/ or http://www.ipchicken.com/ to see the IP address of the computer that you're currently using.

The host that you select to be the place were your pages reside (see Hosting) will have two domain name servers.

You will need to know the IP addresses of those DNS servers when you select and register your domain name (see Domain names)