Why almost every large website uses one
Without a CDN, every visitor worldwide would request files from the same origin server, regardless of their own location, creating both slower load times for distant visitors and a single point of load concentration. Distributing that load geographically is one of the most cost-effective ways to improve perceived site speed at scale.
Caching introduces its own complexity
Because edge servers store copies rather than always fetching the latest version, site owners have to manage how long content stays cached and how to invalidate that cache when the underlying file changes, otherwise visitors can briefly see outdated content after an update.
Frequently Asked Questions
Does using a CDN mean a site no longer needs its own server?
No. The origin server is still where the actual content is managed and updated; the CDN is a caching and distribution layer in front of it, not a replacement for it.
Do small websites need a CDN?
It matters less for low-traffic sites with a geographically concentrated audience, but even smaller sites often use one for the added speed and the traffic-absorbing security benefits, since many CDN services offer a free or low-cost tier.