A CDN (Content Delivery Network) is a network of servers spread around the world that keep copies of your website close to your visitors. Instead of everyone fetching your site from one distant server, each visitor is served from a nearby point — so pages load faster, your origin server is protected from spikes, and attacks are absorbed before they reach you.
When your website lives on a single server, every visitor — whether next door or on another continent — has to reach that one machine. The further away they are, the longer each request takes, and the busier your server gets. A traffic spike, a campaign, or a sudden burst of visitors can slow everything down or take the site offline. A CDN removes that single bottleneck.
Three words explain how a CDN works. The "origin" is your real server, where your site actually lives. The "edge" is the CDN's global network of servers. "Caching" means the edge keeps a ready-made copy of your pages, images, CSS and JavaScript. When a visitor arrives, the nearest edge serves the cached copy instantly, and only contacts your origin when it needs something fresh.
Distance is time. Serving a visitor from a city near them instead of a server thousands of kilometres away cuts the round-trip delay dramatically. Because the edge already holds your content, there is no waiting for your origin to generate the page. The result is faster first paint, quicker images, and a site that feels instant — which also helps search rankings and conversions.
The edge absorbs the bulk of your traffic, so your origin server does a fraction of the work and stays healthy during busy periods. If your origin briefly hiccups, the CDN can keep serving cached pages so visitors still see your site. One viral post or a marketing push no longer means downtime.
Because all traffic passes through the edge first, the CDN can filter it. Malicious requests, bot floods and many denial-of-service attacks are absorbed at the edge before they ever reach your origin. Add a web application firewall (WAF), rate limiting and automatic HTTPS, and your site is protected without you running security software yourself.
There are two ways to get content onto the edge. With a "Pull CDN" you keep your existing site/server, point your domain at the CDN, and the edge automatically fetches (pulls) and caches content the first time it is requested — the simplest way to put an existing site behind a CDN. With a "Push CDN" you upload your static files directly to the CDN's storage and serve them from there, with no origin server of your own to maintain.
High-traffic articles, images and video load fast everywhere and survive sudden spikes after a big story.
Faster product pages mean more sales; the store stays up during campaigns, launches and flash sales.
Static assets and cacheable responses are served from the edge, cutting load and latency for users everywhere.