DNS, How The Internet Keeps Track of Names

The way computers communicate is, in a way, very similar to something very familiar: the postal system that delivers letters and packages. Here''s how...

The Internet is just what the name suggests, a large inter-connected set of networks. But those networks are pointless without the one part that forms what is called their ''end-nodes'', otherwise known as computers. Those computers often need to share information because the people who use them want to share information.

But, in a system where there are millions of separate computers, how can you enable them all to communicate? One very important feature of that solution is performed by something called DNS, the Domain Name System.

Every part of a network that is going to send or receive information is assigned an IP address. That''s a numeric identifier that uniquely specifies a particular ''node'', such as a computer, a router that directs traffic or other component. They look like this: 209.131.36.158

But those numbers are more difficult for people to remember and work with. They also aren''t very attractive from a marketing perspective. So, a naming system was layered on top of some of them, mostly the computers involved, though routers have names, too.

But once you have a system that associates a unique IP address to a given name, you need some way of keeping track of all of them. That''s carried out by several different pieces of the system: Name Registrars, DNS Servers and other components.

The Name Registrars, overseen by IANA (Internet Assigned Numbers Authority) and other international bodies, provide and keep track of domain names. When you register with GoDaddy or any of a hundred other intermediate companies, ultimately that information makes its way into a number of specialized databases stored inside DNS Servers.

A DNS Server is the hardware and/or software that tracks and forwards the IP Address/Domain Name pair from one place to the next. In many cases, there are a number of them between your browser and the remote computer you want to share information with.

Suppose you request information from, say, Yahoo''s site by clicking on a link on their site. DNS resolves (translates) the name of WHO IS making the request and OF WHOM, to addresses, then passes the request through the network to the requested IP address. The requested data is then passed back through the mesh of network components to your computer and displayed in your browser.

Whether the communication is between a desktop computer and a server somewhere, or between one server and another, the process is essentially the same. DNS servers translate names into IP addresses and the requests for data are forwarded on.

In some cases those DNS servers are part of a specialized network computer whose sole job is to do the translation and forwarding. In other cases the DNS software may reside on a server that also houses a database of general data, or stores email, or performs other functions.