juniorCaching
What is a CDN (Content Delivery Network)?
Updated Apr 28, 2026
Short answer
A distributed network of servers that caches content close to the user's geographical location.
Deep explanation
Caching is essential for performance optimization. A distributed network of servers that caches content close to the user's geographical location. By reducing the need to access slower storage layers (like HDDs or remote databases), systems can achieve much lower latency.
Real-world example
Storing the results of a complex database query in Redis.
Common mistakes
- Not setting a TTL, leading to the cache growing indefinitely or serving very old data.
Follow-up questions
- Is cache persistent?