DNS (Domain Name System) is the hierarchical system designed to translate human readable information (such as a domain name, website, or other internet-based resource) into the actual addressing protocols used by computers to navigate and locate information on the Internet. This sounds complex, and can be at times, but the basics of it are actually very simple.
Computers route information and find things on the internet using IP addresses (IP stands for Internet Protocol). Everything connected directly to the Internet has a unique IP address, which is reached through the interconnected routers, peers, bridges and data-pipes that make up the backbone of the Internet. Very few people can remember 220.127.116.11, for example, and since these change sometimes, an easy to use human-understandable name, such as www.easydns.com is necessary.
What DNS does is provide a system to track what IP address that name will resolve to, and answer back quickly and authoritatively so a browser can get the website with no noticeable interruption.
Here's what happens when you go to view a website:
- Your computer queries your local DNS resolver for where to go -- and waits patiently for the resolver to do all the heavy work.
- The local DNS resolver queries the root servers for the registrar responsible for the information, gets a reply and goes on to the next step.
- The DNS resolver now asks the registrar for the name(s) and address(es) of the server(s) responsible for knowing all the details about the domain name. These are called nameservers.
- The DNS resolver now queries the nameservers (which it knows to be authoritative because it started from the root) for the IP address of the server that hosts the web site you've clicked to view, and receives it.
- The local resolver sends that IP address back to your computer, which can now look it up on the internet in a format that makes sense to it, rather than to us.