CDN
Definition
Content Delivery Network - a network of servers globally that caches copies of your content, ensuring faster delivery to users and improved performance.
Use Cases
- Netflix: Delivering video streams with low startup time and minimal buffering for viewers worldwide — Uses a CDN approach by placing copies of popular content on servers close to users (edge caching) so most video segments are served locally rather than from a distant origin (Faster playback start, reduced buffering, and lower load on central origin infrastructure during peak viewing times)
- Amazon: Speeding up product image and static asset delivery for e-commerce pages globally — Uses Amazon CloudFront to cache static assets (images, CSS, JavaScript) at edge locations and serve them over optimized network paths (Improved page load times for shoppers in different regions and reduced origin server bandwidth usage)
- Spotify: Efficient delivery of static web assets for the Spotify web player and marketing sites — Uses CDN caching to serve static files from edge locations close to users, reducing round-trip latency to the origin (More responsive web experiences and reduced traffic spikes hitting origin servers during campaigns and releases)
Provider Equivalents
- AWS: Amazon CloudFront
- Azure: Azure Front Door
- GCP: Cloud CDN
- OCI: OCI Content Delivery Network
Frequently Asked Questions
- What's the difference between a CDN and a load balancer?
- A CDN caches and serves content from edge locations close to users to reduce latency and origin traffic. A load balancer distributes incoming requests across multiple origin servers to improve availability and handle more traffic. Many architectures use both: the CDN in front for caching, and a load balancer behind it for routing to healthy origin servers.
- When should I use a CDN?
- Use a CDN when you have users in multiple regions, serve static assets (images, videos, downloads, CSS/JS), want faster page loads, or need to reduce bandwidth and request load on your origin. It’s also helpful for handling traffic spikes (product launches, live events) because edge caches absorb repeated requests.
- How much does a CDN cost?
- CDN pricing is usually based on data transfer out (GB served), number of requests, and sometimes extra features like WAF, DDoS protection, or advanced routing. Costs vary by region (some geographies are more expensive) and by cache hit ratio (better caching typically lowers origin bandwidth and can reduce total cost).
Category: networking
Difficulty: intermediate
Related Terms
See Also