文档介绍：How Domain Name Servers Work
by Marshall Brain
If you spend any time on the sending e-mail or browsing the Web, then you use domain
name servers without even realizing it. Domain name servers, or DNS, are an incredibly
important pletely hidden part of the , and they are fascinating! The DNS system
forms one of the largest and most active distributed databases on the . Without DNS, the
would shut down very quickly.
In this edition of HowStuffWorks, we will take a look at the DNS system so you can understand
how it works and appreciate its amazing capabilities.
The Basics
When you use the Web or send an e-mail message, you use a domain name to do it. For
example, the URL "" contains the domain name
. So does the e-mail address "******@."
Human-readable names like "" are easy for people to remember, but they
don't do machines any good. All of the machines use names called IP addresses to refer to one
another. For example, the machine that humans refer to as "" has the IP
address . Every time you use a domain name, you use the 's domain
name servers (DNS) to translate the human-readable domain name into the machine-readable IP
address. During a day of browsing and e-mailing, you might access the domain name servers
hundreds of times!
Domain name servers translate domain names to IP addresses. That sounds like a simple task,
an