What is DNS
Short for Domain Name Service, DNS servers throughout the world are what makes browsing a comfortable human experience instead of a numeral nightmare.
The idea behind DNS servers
The post office needs to know your address to deliver mail to you. The world at large needs to know your site's address to deliver users to you. This address, called an <IP address>, is a simple string of numbers.
Of course, no one is going to memorize numbers like 209.85.135.99 (Google) or 69.63.190.10 (FaceBook). We have enough trouble managing our phone numbers, thank you. And just like in a phone book, where we assign each number an easily recognizable name, DNS servers allow us to assign each IP address a domain name, like www.google.com (for 209.85.135.99) or www.facebook.com (for 69.63.190.10).
Over 10 million DNS servers, scattered throughout the world, keep track of these name-address pairs. People will not be able to reach your site by its domain name until news of it has spread through this network. (This process, called DNS propagation, is why sometimes a domain name only kicks in a few hours after it's assigned to an IP address.)
Working with DNS servers
When you purchase your hosting plan, you will likely be given by your hosting provider two or more DNS server addresses. If you bought your domain name from another supplier, you will need to give him that information.
Most domain name suppliers offer you an online dashboard through which to manage your domains. On this dashboard, you'll usually find an option along the lines of "Change DNS addresses" or "Host your site elsewhere". When clicked, you will see the current DNS addresses of your domain name—by default, two of the domain name provider's, which associate your domain name with a temporary landing page. When you change these to the addresses given to you by your hosting provider, you will associate your domain name with your actual IP address.
Important: Your hosting provider must know the actual domain name you're associating with your site, otherwise the name-address entry on his DNS server will be wrong.
