What is a CDN?
A CDN (Content Delivery Network) is a geographically distributed network of servers designed to deliver content (like images, scripts, and videos) to users faster by serving them from locations closest to them.
Why Use a CDN?
1. Faster Load Times
Content is cached at edge locations, reducing latency.
2. Reduced Server Load
Requests are offloaded from origin servers, improving scalability.
3. Improved Availability
CDNs handle traffic surges and DDoS mitigation.
4. Global Reach
Serve users from around the world with consistent performance.
How Does a CDN Work?
When a user accesses a website, the CDN routes the request to the nearest edge server. If the requested content is cached, it’s served immediately. If not, it’s fetched from the origin server, cached, and delivered.
Common CDN Providers
- Cloudflare
- Akamai
- Amazon CloudFront
- Fastly
- Bunny.net
Use Cases
- Hosting static assets (JS/CSS/images)
- Video streaming
- API acceleration
- Protection from DDoS
Example: Cloudflare + NGINX Setup
server {
listen 443 ssl;
server_name example.com;
location / {
proxy_pass http://localhost:3000;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
}
}
After this, enable Cloudflare proxy for your DNS A record.
When Not to Use a CDN
- Small internal applications not exposed to the internet
- Highly dynamic content with sensitive caching
Conclusion
A CDN can drastically improve your website’s performance, security, and reliability. Whether you’re deploying a global-scale app or a high-traffic blog, understanding CDN usage is a must-have skill.