Content Delivery Network
A CDN caches static content at edge nodes worldwide, answering user requests nearby to reduce latency and origin load.
Purpose
Accelerate content delivery, reducing origin load and bandwidth cost.
Mechanism
User requests are DNS-routed to the nearest edge node. Cache hits return directly; misses fetch from origin and cache. Cache keys (URL/Cookie/Vary) control caching granularity. Cache invalidation (purge) refreshes content.
Use cases
- Content acceleration
- Global distribution
- Bandwidth optimization