When you type "chron.com" into your computer's Web browser and press enter, behind the scenes, a system of Internet connected devices is working together across hundreds or thousands of miles to turn that nine-character domain name into something that the computers on the Internet can use to deliver this article to you. The Domain Name System is the Internet's internal address book and it ensures that customers can always find your business's website, too.
While we see domain names when we use the Internet, you don't actually need to use them. For example, if you plug "18.104.22.168" into your Web browser's address bar, you'll go to Google. These numerical addresses, called Internet Protocol addresses, are how the Internet really works. They're like telephone numbers for websites, while domain names are like the entries in your cell phone's address book that let you call friends without actually dialing their numbers.
Domain Name Registration
Every site that has a domain name went through the process of registering the name with a third-party domain registrar. Domain registrars are companies designated by the Internet Corporation for Assigned Names and Numbers (ICANN). They give you the right to control how that domain name gets used and where it gets pointed on the Internet.
A domain name gets registered with multiple servers, each of which is responsible for a different part of the name. When you register a name like example.com, your registrar's "authoritative" name servers track the actual IP address for your site. However, to get to your registrar's servers, computers on the Internet need to know to go there. Since they don't, DNS has servers for each top-level domain, such as .com or .net. The server for ".com" knows where to go to find the information for "example."
When you plug a domain name into your Web browser, your computer first looks at a file that it stores, called a "hosts" file, to see if it knows where to go. If there isn't an entry in the hosts file, it asks the DNS servers that are tied to your Internet connection. In many cases, they've already looked up the site for someone else and can send you along without having to do another look up. If they haven't, those servers send a request to a root name server that forwards the request to a TLD name server. The TLD name server sends your ISP's name server to the authoritative server. Finally, the IP address gets sent back to your ISP's server -- which it forwards to you so that you can go to the page you originally requested.
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