DNS explained in plain English

Explanations of DNS can get quite technical, yet understanding it is important if you have email or website hosting.
Article by Simon Steed
Simplepage Website Uptime Monitoring

Table of contents

What is DNS?

DNS is an acronym that stands for: ‘Domain Name System’. It sounds very technical, but it’s really designed to work just like a giant telephone directory: it converts website names into numbers through a lookup process.

How does DNS work?

A computer that is attached to the internet will be given an ‘IP Address’. This address is a set of numbers that act like your telephone number - with the right settings, ‘dialling’ this number will allow you to connect to your computer from anywhere in the world. But you can imagine how difficult the web would be if you had to remember the number for every website you’ve ever visited!

This is where DNS can help! Rather than having to remember hundreds of numbers in a giant address book, DNS becomes our public address book, so now you only have to remember the ‘domain name’ (in this case: ‘google.com’).

When you enter ‘google.com’ in your browser, the first lookup done is to contact the ‘com’ top level domain name (TLD) server and ask where ‘google’ points to. At the time of writing, google.com points to This is the ‘IP address’ which your browser will then connect to in order to fetch a web page from Google.

Both Internet and Web Use DNS

DNS is such a useful system that other areas of the Internet also use DNS. For example, if you send an email to someone, the servers will do a lookup on the ‘MX record’ (similar to a ‘DNS Record’ but for emails). Rather than looking up the IP address of the computer serves the web pages for the domain, an MX lookup will tell you what server handles mail for that domain name.


You can also create subdomains underneath the domain names you own. These subdomains pre-fix the rest of the domain and, if needed, can actually point to a separate IP address and computer. For instance, suppose you owned mywebshop.com, you could create checkout.mywebshop.com as a subdomain which points to a separate server which could handle online purchases.

Domains and SSL

An SSL certificate is designed to ensure your are connected to the server you think you are. They help verify the authenticity of the host you are accessing. The reason domains and subdomains are important to website and business owners, in addition to helping identify your services and brands, they may also help your business save costs. SSL Certificates are sold on a per-domain basis. This means you would need to buy and install a separate one for each domain you run.

In reality, you can use these domains however you wish to help boost your brands, visitor's confidence in your company and also to offer nice and tidy web addresses that are memorable and increase the chances your visitors return to buy from your again!