Ever wonder how the Internet knows what information to bring
up in your web browser when you type in the URL of your favorite website? This
is all taken care of through the Domain Name System (DNS).
Each web and email
server has a numerical address that serves as the unique address for that
machine. The Domain Name System is responsible for maintaining the relationship
between this numerical address and the friendly domain name you
generally use to connect to web pages and to send email. You can
simply type in www.google.com instead of
having to remember 18.104.22.168 to do your daily searches.
When you type in a URL, the first thing your computer does
is ask a DNS server what the actual numerical address is. Then, you are
connected to that address, but still shown the friendly name you typed. Because
of this system, there will often be a delay when your website moves to a new server as
the Internet learns the new numerical address of your domain name. This is
referred to propagation.
All of the servers that are responsible for knowing
these addresses are updated on various schedules, some updating more quickly than
others. Which server a site visitor is connected to will dictate whether or not
they view content on your new server or old one. While highly detailed, DNS and systems like it keep the
Internet an easy, friendly world to navigate.