A Content Delivery Network (CDN) stores copies of your content on servers around the world. When users request content, it's served from the nearest location, reducing latency.
How CDNs work
- Your origin server hosts the original content
- CDN edge servers are deployed globally
- Content is cached on edge servers
- Users receive content from the nearest edge location
CDN benefits
- Faster load times: Content served from nearby servers
- Reduced server load: Origin handles fewer requests
- Better availability: Content survives if origin goes down
- DDoS protection: Traffic distributed across network
- Lower bandwidth costs: Caching reduces origin bandwidth
What to serve via CDN
- Static assets (images, CSS, JavaScript)
- Video and audio files
- Software downloads
- Entire websites (static sites)
CDN and Core Web Vitals
CDNs directly impact:
- TTFB: Faster initial response from edge servers
- LCP: Faster delivery of hero images
- FCP: Quicker delivery of initial resources
Related Terms
Caching
The process of storing copies of data in a temporary storage location so that future requests can be served faster.
Latency
The time delay between a user action and the system's response, often referring to network delay in web performance.
Server Response Time
The time it takes for a server to respond to a request from a browser, measured from request initiation to receiving the first byte of response.
Time to First Byte (TTFB)
A performance metric that measures the time between the request for a resource and when the first byte of a response begins to arrive.