Content Delivery Network (CDN) : Jargon Buster

A Content Delivery Network (CDN) can help improve a website’s availability and performance by distributing the hosting of content across a whole network of servers.

This delivery network usually spans multiple data centres around the world and content is automatically served to the individual website visitor from whichever is geographically closest. The resulting reduction in network delay on every file request can deliver web pages noticeably faster.

Undoubtedly websites with an international audience benefit most from implementing a CDN, potentially saving seconds on every page load. But there is value for those with a more domestic focus too. By shifting a significant proportion of the work of content delivery to the CDN the load on the originating web server is lightened, helping to deliver more consistent performance, even during traffic spikes. A combination of super-fast servers and proximity to major networking hubs also tends to give a good Content Delivery Network the performance edge compared to the average hosting solution.

A common setup is to use a CDN for serving assets such as images, CSS and JavaScript – relatively static content that makes up the majority of a typical web page. Each time a visitor’s browser requests one of those files the request hits the closest CDN server rather than the main web server. In combination with other content optimising techniques such as code minifying, compression and caching this approach can significantly improve page load times. It is cost effective too with the entry price for adding a Content Delivery Network as little as £10 per month and a relatively low technical barrier to adoption.