What is a Content Delivery Network (CDN)?

Discover what a content delivery network (CDN) is, how they work, and how they can help you improve your search engine ranking positions.

Content delivery networks, or CDNs, play a crucial part in a website’s user experience. It is a tool that you should certainly consider if you want to speed up loading times for all users across the globe, especially if your website is laden with high quality images and videos which could otherwise slow down the page loading times drastically.

Without a content delivery network, your content origin servers (the servers your content is originally stored on) have to respond to every single user request. If traffic becomes especially high during peak times this can often lead to server failure as the system becomes overloaded and unable to cope.

What is a content delivery network?

A content delivery network is a group of geographically placed servers around the world that work together to minimise delays in loading web page content and assets.

By reducing the physical distance between the server and user it is easier to optimise the performance of the website.

How do CDNs work?

If a user wanted to access a British website from America, their request, without a CDN, would have to travel across the Atlantic all the way to the UK to be granted access, which, as you can imagine, would lead to severe delays in content loading.

A CDN’s objective is to reduce latency – the time it takes between submitting a request and the website fully loading on your specified device.

They work by storing a cached version of your website content in multiple geographic locations around the world. These are known as PoPs or Points of Presence. Each PoP will contain their own caching server and its role is to deliver that content to the users in their set geographical areas when requested.

Gone are the days where we could wait up to a minute or more for webpages to load, if a website doesn’t load quickly, chances are your user may get bored and click off. So, the more you can optimise your loading times for your website the better your engagement stats are likely to be.

Content delivery networks also compress file sizes using such methods as minification. By reducing the file sizes there is less data to transfer which means images, content and assets load up faster for your users.

It isn’t just website content that CDNs transfer. They can also deliver 4K images, HD- quality video, audio streams and even software downloads such as games, apps and OS updates.

Basically, any data that can be digitised can be delivered through a content delivery network.

The SEO opportunity

By having CDNs across the world, that 3 second website load time suddenly decreases to as little as 1 second.  It also relieves pressure off the origin servers to ensure the website works efficiently, helping to contribute to a good user experience for all.

With Google’s recent Core Web Vitals update, user experience and content delivery now play a much more vital role in determining search engine rankings.

If your website is slow and not optimised, your rankings may well suffer. So, this is the perfect time to check your website speeds, your content file sizes from a user experience perspective, and consider if a content delivery network is a good investment for your company.

CDNs have been helping websites all around the world improve their speeds and user experience for almost 30 years and there are a multitude of different companies and setups you can go with.

If you are interested in investing in CDNs for your website, we can support you with this

Alternatively if you are interested in discovering other ways of optimising your website, have a look at one our latest blog post and find out our 8 tips to improve your website’s user experience.


We are an award-winning, full-service digital marketing agency based in Thatcham, Berkshire.

Our goal is to help businesses understand the true value in digital marketing and set out to help those businesses develop and implement new technology and processes to deliver a marketing strategy in line with their goals.

Partnership is key to our digital marketing approach. We work closely with you to identify what will drive the most value for your business and provide a range of digital marketing services to achieve it.