What It Is
A content delivery network, or CDN, keeps copies of your website’s images, stylesheets, scripts and sometimes whole pages on servers spread across many cities. When someone visits, files come from the closest server instead of traveling all the way from your main host. It is like a chain store stocking popular items in every neighborhood, so customers do not have to drive to the central warehouse.
Why It Matters for Your Business
A CDN makes pages load faster, especially for visitors far from your server, and takes pressure off your hosting during busy times. Many CDNs also add security features such as DDoS protection and a web application firewall. Even a local Chicago business benefits, because mobile visitors and image-heavy pages load more smoothly and search engines favor fast sites.
Good to Know
After changing your website, a CDN may keep showing the old version for a while because it is serving stored copies. Most CDNs have a "purge cache" button to clear them. Setting up a CDN sometimes involves changing your nameservers or DNS records, so make sure email records come along, or your email could stop working.