What is a CDN? How does a CDN Work? | Imperva

Content delivery networks (CDN) are the transparent backbone of the Internet in charge of content delivery. Whether we know it or not, every one of us interacts with CDNs on a daily basis; when reading articles on news sites, shopping online, watching YouTube videos or perusing social media feeds.

No matter what you do, or what type of content you consume, chances are that you’ll find CDNs behind every character of text, every image pixel and every movie frame that gets delivered to your PC and mobile browser.

To understand why CDNs are so widely used, you first need to recognize the issue they’re designed to solve. Known as latency, it’s the annoying delay that occurs from the moment you request to load a web page to the moment its content actually appears onscreen.