How Domains Work.

When you use the Web or send an e-mail message, you use a domain name
to do it. For example, the URL "http://www.techarena.in" contains the
domain name techarena.in. So does the e-mail address
"someone@techarena.in."

Human-readable names like "techarena.in" 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 "www.techarena.in" has the IP address
207.58.143.178. Every time you use a domain name, you use the
Internet'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, and it would be -- except for five things:

*There are billions of IP addresses currently in use, and most
machines have a human-readable name as well.
*There are many billions of DNS requests made every day. A single
person can easily make a hundred or more DNS requests a day, and there
are hundreds of millions of people and machines using the Internet
daily.
*Domain names and IP addresses change daily.
*New domain names get created daily.
*Millions of people do the work to change and add domain names and IP
addresses every day.

The DNS system is a database, and no other database on the planet gets
this many requests. No other database on the planet has millions of
people changing it every day, either. That is what makes the DNS
system so unique!