Tutorials & Guides

The Basics: Domains, DNS and Name Servers

Photo by Deanna Ritchie on Unsplash

How does the browser know which website to load when you type in the address?

There might be a bit more to it than you might expect, so lets explore the world of domains, DNS and name servers and hopefully by the end of it you will have a better understanding of how it all works.

As always with the "Basics" series, I will be glancing over some details and simplifying some processes for the sake of, hopefully, keeping things simpler and easier to understand.

Domains

Mailboxes in the desert
Photo by Marius Christensen / Unsplash

You can think of a domain as like a "person". When you type in the name of the domain in your browser, the browser will find the location of the domain and transfer you to their location.

So if domains are like people, but how does the browser actually know where they are?

This is where the DNS comes into play.

Domain Name System (DNS)

Kat flipping through the pages of the dead American soldiers at the Vietnam Veteran’s Memorial in DC. I remember looking at her nail polish and watching her fingers scan over one name, one person, two people, seven, four hundred, thousands. There were tear stains on the glass.
Photo by Brittany Colette / Unsplash

At the risk of sounding old, the DNS is like a "phonebook" for the domains. Like a phonebook, the DNS have all the addresses and information about any given domain within, and will tell you exactly where a domain website is located (in this case IP address).

For example, when you type in "markeliasen.com" into your browser, the browser does not just know where a domain website is at. So the browser will first need to check the "phonebook" (DNS) of the domain to find out where to send you.

But just as in the real world, there are more than just 1 phonebook so how does the browser know which one to use?

Name Servers

I do like what is obviously, well, the obvious. And this sign at my favorite new brewery, just a few feet from the door, is delightfully obvious.
Photo by Jamie Templeton / Unsplash

If the DNS is like a phonebook, the name servers is what tells you exactly which phonebook you can find the details in. This is how the browser will know, of all the thousands or more DNS'es which exists, which one specifically to look in to find the correct details for a given domain.

But that leaves a question. How does the browser know the name servers of any given domain?

Bonus: "Domain Name Registrar"

Unite
Photo by Davi Mendes / Unsplash

It's hard to talk about name servers without also talking about what a "domain name registrar" ("registrar") is.

A domain name registrar is a company that manages the reservation of Internet domain names - Wikipedia

For example, if you register a .com domain, the domain reservation is handled and managed by ICANN who is the governing entity for .com's (among others); likewise if you were to register a .co.uk domain, it would be handled by Nominet.

This is where a domain's name servers will be registered to a domain.

Every DNS knows which registrar to ask to get the name servers of a domain, based on the domains extension (.com, .co.uk etc).


Conclusion

I hope this helps your better understand what domains, DNS'es and name servers are and how they work. Knowing this is important, especially if you are a web developer.

If there is anything you believe I didn't clarify properly or you would like me to elaborate on, just let me know!