Content Delivery Networks, or CDNs, keep much of the modern web running smoothly. They are behind faster page loads, fewer outages, and safer browsing experiences. If you have wondered how they work or whether you should use one, here are the ten questions people ask most — with answers in plain language. For more advanced strategies that combine multiple providers, see the Top 10 Questions About Multi-CDN.
1. What is a CDN and how does it work?
A CDN is a network of servers in many locations. It stores copies of website content on those servers so they can be delivered from a place closer to the visitor. Instead of every request going back to the main origin server, a CDN routes the visitor to the nearest edge server. The shorter the journey, the faster the response.
2. What are the main benefits?
The obvious gain is speed, but CDNs also add reliability, scalability, and security. By spreading traffic across many servers, they reduce the risk of overload. They can absorb DDoS attacks that might otherwise take a site offline. And they make it easier to handle sudden traffic spikes without slowing down.
3. How does a CDN make a site faster?
Speed comes from reducing latency — the time it takes for data to travel between a client and a server. CDNs cache static files — images, scripts, style sheets — on edge servers. When these files load from a nearby location, pages appear faster. Even dynamic content can benefit if the CDN optimizes the route or keeps a secure, persistent link to the origin.
4. Is it just for static files?
Not anymore. CDNs now deliver everything from dynamic HTML pages to high-definition streaming video and large file downloads. Live broadcasts, software updates, and even interactive applications can all be served through a CDN.
5. How does a CDN help with security?
Because traffic flows through its servers, a CDN can stop threats before they reach the origin. Many offer built-in DDoS protection, block malicious requests through a Web Application Firewall, and enforce encrypted connections with TLS. Some also detect and control unwanted bot traffic.
6. Does a CDN replace my hosting?
No. Hosting is where your site’s files live; the CDN distributes copies of those files around the world. Think of the host as the library archive and the CDN as a network of branch libraries that keep popular books on hand for local visitors.
7. How do I choose a provider?
It depends on where your audience is, how much traffic you have, and what features you need. A global e-commerce site might need wide coverage and strong security. A regional news site may prefer a provider with more points of presence close to its core readership. Pricing, support, and integration with your platform all play a role. If your audience is truly global or downtime is unacceptable, you may want to consider a Multi-CDN approach.
8. How much does it cost?
Prices vary. Some providers have free plans for small sites. Others charge based on egress volume, with rates that drop as usage grows. Subscription plans are common for enterprise services. The right choice balances cost with performance and features.
9. Can it help with SEO?
Yes. Search engines reward fast-loading sites and penalize those that frustrate visitors. A CDN improves load times, reduces bounce rates, and helps keep a site stable during heavy traffic — all of which can contribute to better rankings.
10. How do I set one up?
Most CDNs follow the same basic process: you add your domain to the CDN’s control panel, adjust your DNS settings so traffic flows through the CDN, and fine-tune caching and performance rules. Many platforms and content management systems offer direct integrations that make setup even quicker.
For an overview of strategies that combine multiple providers, see Top 10 Questions About Multi-CDN.