What is CDN?
Content Delivery Network — copies of your site spread around the world so it loads quickly wherever your visitors are.
CDN stands for Content Delivery Network. It is a network of copies of your site stored on servers around the world, so visitors always get pages from a server close to them.
Imagine selling a popular book but keeping all stock in one warehouse in a single city. Everyone worldwide waits for delivery from there. A CDN is like having small warehouses in every major city — a customer in Tokyo gets their book from Tokyo, not from the other side of the world. Content is nearby, so it arrives fast.
In the same way, a CDN stores copies of your images, text and files on servers in many countries. When someone visits your site, everything is fetched from the nearest location, which makes the page load much faster.
Why does a CDN matter for your business?
Speed affects both visitor satisfaction and where you rank in Google search results. A slow site frustrates people and sends them away; a fast site feels professional and keeps them engaged.
A CDN also makes your site more resilient. If many people visit at once, or one server has problems, the network can spread the load so the site still works. It also offers some protection against certain overload attacks.
CDN in practice
Say you run an online shop in Manchester but get customers across Europe. Without a CDN, a customer in northern Finland would experience the site as slower than someone in Manchester. With a CDN, product images load at similar speed regardless of location.
During a campaign where thousands of people click through at once, a CDN spreads traffic so the site does not crash at the moment it matters most.
Common questions about CDN
What does CDN mean?
CDN means Content Delivery Network — a global network of servers that store copies of your site so it loads quickly wherever the visitor is.
Does my website need a CDN?
If you have visitors from different regions or want the fastest possible load times, a CDN is almost always worthwhile. Many modern web platforms include one without you needing to think about it.
Does a CDN cost money?
There are both free tiers and paid options. For most small businesses a free or low-cost tier is enough, and the cost is often outweighed by a faster site and happier visitors.
Related terms
Serverless
There are still servers — you just do not need to worry about them. Someone else has the headache. You have the app.
API
Application Programming Interface. Think of a waiter who takes your order (request) and brings the food (data) from the kitchen (server).
Cache
Stored data that loads instantly instead of being fetched again. Often the reason your site feels fast — or why changes do not show up.
Cloud
Someone else's computers. Servers in massive data centres you rent instead of own — AWS, Google Cloud, Azure.
Database
Where all your data lives — users, orders, everything. Lose the database and you lose everything, which is why we back it up.
DNS
The internet's phone book. Translates zorc.se into an IP address so your browser finds the right server.