What actually is DNS?

This was a question that came up in conversation with some of the non-techy team here at Vidatec. Technology is full of acronyms that, for those with the knowhow, seem pretty simple - but as the saying goes, it’s only easy if you already know the answer! To help out my curious colleagues, I decided to write up a quick intro on DNS. 
 
The DNS, or Domain Name System, is essentially the phonebook of the internet. While humans can communicate with one another by calling each other’s phone number, the internet instead uses IP addresses – a series of numbers that uniquely identifies every device connected to the web.  
 
Imagine that your boiler has broken down, so you want to get a local repair man – Pete the Plumber - to fix it. Before you can have him come out and take a look, you first need a way to contact him. In the days before the internet, this meant that you would have to take the time to look up his contact details in a phonebook. Only once you’d gone to the phonebook, found his name and got the phone number listed for him, could you contact Pete and arrange for your boiler to be fixed. 
 
Behind the scenes, the internet is very similar. These IP addresses act like a phone number but for a website. For example, the IP Address for google.com is 216.58.206.110. However, to you or me, this means very little, we’d just type ‘google.com’ into the address bar and wait for the page to load. 
 
So, we’ve typed ‘google.com’ into the address bar and our computer knows it needs to load the page. Before it can do that though, much like we needed the phone number of Pete the Plumber, our computer needs the IP address of google.com. This is where it can turn to its phonebook - a DNS server. 
 
Once our computer has reached out to a DNS server and looked up the IP address of google.com, it can now communicate with Google and load the web page. And, a little like a speed-dial, it will save the IP address, so it doesn’t need to go to a DNS server every time you try and load Google.  
 
In the background, this process will take place for every website you try and access on your computer, phone, or any other internet connected device. However, since it saves the result, this will only happen when you first access a website, or when your computer wants to check it has the most up to date IP address for that website, helping ensure it never slows down your browsing experience. 
 
Much like there are different phonebooks, there are many different DNS providers. Your WiFi hub will automatically pick one for you, meaning you never even have to worry about it. However, you are also able to change this in your computer, phone, tablet or router’s settings, which can provide numerous advantages including speed and privacy. If you’re interested in changing your DNS, or want to learn more about how they work, Cloudflare provide an excellent guide here
 
Hopefully that explanation makes sense! Please do keep checking back on the Vidatec blog for simple introductions to other tech terms.

Olly Namey - Junior Web Developer