What is Domain Name System (DNS)?

Domain Name System is an essential component for the functionality of the internet and private networks. Its job is to translate domain names (human friendly name, like: google.com) and host names (device name, like: BobComputer or HomeComputer) into a numerical identifiers or IP addresses* (192.168.5.6) to locate...

Domain Name System is an essential component for the functionality of the internet and private networks. Its job is to translate domain names (human friendly name, like: google.com) and host names (device name, like: BobComputer or HomeComputer) into a numerical identifiers or IP addresses* (192.168.5.6) to locate devices in a network, this can be locally (private network) or worldwide (through the internet).

In other words, DNS is a matching system; it matches domain names to IP addresses.

This is what happens behind the scene:

1-  When you are using your web browser and you type an URL, you are actually typing an alias.

When you type, for example – https://pureinfotech.com -, your web browser doesn’t really know the actual location for this URL, so it sends a DNS request to a DNS server in the internet.

2-  The DNS Server receives the request and looks for an IP address (1.2.3.4) that matches the URL that you requested. There are many of these server all over the world, and they must always be synched.

3-  Once a match is found, the DNS server will return the corresponding IP address for the URL to your browser and then the web browser will contact the website.


DNS Query

This process will be repeated every time you want to visit a website (The DNS process is usually fast, most of the time you will not notice it). Some web browsers, like Google Chrome, have by default the option to save all the IP addresses for every website that you visited. In theory this is a good thing because the DNS process, even though it’s fast, it takes time and doing this will speed up your browsing experience, but there is a down side, if for some reason the IP address for a website that you want to visit changes, you will not be able to get there because the web browser will try to contact the website with the saved DNS records instead of contacting a DNS server.

Remember that the Domain Name System (DNS) is our friend; just imagine how hard would it be for us to remember a numerical address for every website that we visit, 74.125.65.99 (Goolgle.com), 74.125.95.93 (youtube.com), 69.63.189.11 (facebook.com); etc. How many would you think you could memorize?

*In simple terms an IP address is an identifier for a computer or device on a computer network; it works in the same way as your house address.

 

About the author

Mauro Huculak is a Windows expert and the Editor-in-Chief who started Pureinfotech in 2010 as an independent online publication. He is also been a Windows Central contributor for nearly a decade. Mauro has over 12 years of experience writing comprehensive guides and creating professional videos about Windows, software, and related technologies, including Android and Linux. Before becoming a technology writer, he was an IT administrator for seven years. In total, Mauro has over 20 years of combined experience in technology. Throughout his career, he achieved different professional certifications from Microsoft (MSCA), Cisco (CCNP), VMware (VCP), and CompTIA (A+ and Network+), and he has been recognized as a Microsoft MVP for many years. You can follow him on X (Twitter), YouTube, LinkedIn and About.me.