The Essential CDN Guide
Content delivery networks (CDNs) are the pipelines of the Internet. Working behind the scenes, they are reshaping how information is consumed online, accelerating web traffic, enhancing user experience and providing every website with the ability to truly go global.
Still, although we all interact with CDN on a regular basis, most of us are only loosely aware of the underlying technology and the nuances of their inner workings.
The purpose of this guide is to help bridge that gap and provide you with the information you need to understand CDNs—what they are, what they do and how they work.
Who is this guide for?
When writing this, we wanted to create something that will be of value to all readers; newcomers and power-users alike.
Having said that, this guide is likely to be most helpful to those of you who are about to start using a CDN and are debating which service to choose.
By combining introductory and in-depth information, this guide will cut through the marketing fluff and help you make an informed decision.
What’s up with the cool graphics?
Thank you for noticing.
Like many underlying technologies, CDNs suffer from an image problem—often being considered dull or even taken for granted. Much like the global satellite array and submarine fiber cables, CDNs represent an intangible infrastructure—they’re not something we can actually feel, touch or even observe.
The accompanying graphics are our way of compensating for the CDN’s innate transparency. Hopefully they also provide for a better reading experience.
Which chapter should I read first?
This is really up to you. Each chapter has been written to be a concise, self-contained unit—so feel free to pick and choose the one that best suits your needs.
If you’re already a CDN power user, you may decide to skip or just browse through some chapters.
If you’re a newcomer to the world of CDNs and are looking for a thorough overview, it’s likely you’ll want to read the entire guide.
So let’s get started . . .
What is a CDN anyway?
Let’s start from the top. A CDN is a network of servers strategically located in different parts of the world. Each server holds a copy of a website's content and serves it to the site visitors within its locale.
By bringing content closer to each visitor, the CDN minimizes site load times and reduces some operational costs, (primarily bandwidth consumption.)
As more and more websites are targeting a global audience, the popularity of CDNs is at an all-time high. At the same time, the price of the service has never been lower.
Today, with many core CDN services being offered for free, and others rented for a relatively low cost, the technology is used by websites of all sizes.
Fact: CDNs are responsible for routing more than half of all Internet traffic.
Why do I need a CDN?
Page load speed plays a critical role in any website visitor’s experience. Studies show that even a one-second load time delay causes a 7% drop in conversions, an 11% drop in page views, and a 16% drop in customer satisfaction.
CDNs are the best way to significantly improve your site’s load time. What’s more, many modern CDNs also help tackle other IT tasks, including website security, load balancing and DDoS attack protection.