Domain Names, IP Addresses and DNS: A Short, Non-Scary Introduction

Some people are afraid of things that sound “techie.” I understand that, but in a lot of cases, people get that way because nobody has ever explained the terms to them. The “techie” terms are particularly complicated or hard to grasp, but you might not have come across a good explanation of what those terms mean.  I’m hoping to change that.  Today, we’ll take a look at Domains, IP addresses, and DNS.  It might sound scary, but have no fear.  If you’ve ever tried to memorize a phone number, you’ll appreciate both the problem of IP addresses, and the solution that domain names and DNS offer.

A domain name, as you likely already know, is a name that is unique to your business, organization, service, or collection of cat pictures. When I type junglebeanscoffe.com into my browser, I expect to be brought to the Jungle Beans website so I can purchase delicious hand-crafted coffee.  You might not realize, however, that your computer has no idea what “junglebeanscoffee.com” means.  The internet doesn’t run on domain names, it runs on something called IP addresses.  IP addresses are sets of four numbers separated by dots.  The actual address of the Jungle Beans website is 70.32.73.65.

Of course, nobody wants to try to remember that. Other than my parents and my wife, I don’t even remember anyone’s phone number without storing it in my phone. Companies will sometimes come up with words and letters to help you dial, like 1-800-flowers or 1-800-go-guard. This works because it’s a lot easier to remember a word than it is to remember a series of numbers. The pioneers who built the Internet as we know it introduced the Domain Name System (or DNS) to remedy the problem with a solution similar the letters on your phone’s number keys. When you register a domain name with DNS, it lets the whole world know what numeric IP address your domain has.  When I type junglebeanscoffee.com into the browser, my computer consults the DNS server it’s attached to and finds that it should send me to 70.32.73.65. It all happens so fast you don’t notice.  The system is quite flexible, which is why you can have more than one domain name point to the same website, and also why you will sometimes find more than one website with the same IP address (but I won’t get into that).

When your web developers launch a new site or make other changes, they’ll sometimes say something like “this requires a DNS change, so it will take a day or so to show up.” Be assured that this is not just some dross your developer has made up to buy him more time.  Changes to DNS don’t go into effect immediately, because when you update the system in one place, it has to update other parts of the system, which then have to update still other parts, and so on.  There are ways to speed the changes up in some cases, but it’s typical for the change to take 24 to 48 hours to show up everywhere.  Once the changes have happened, the old IP address might still be stored in your browser from the last time you looked at your site.  You might need to quit and restart your browser, or even restart your computer, before the changes show up for you. Unlike most things on the Internet, patience is the best policy for these things.

Of course, you don’t need to know any of this to use your web browser to buy coffee.  But next time you type in a domain name, you might take a moment to stop and consider just how much work your computer and the Internet are doing without you even thinking about it.

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