What is CDN (Content Delivery Network)?
Turkish: CDN
A CDN caches static content on edge servers near users, reducing latency, bandwidth pressure, and load on the origin server.
What is a CDN?
A CDN (Content Delivery Network) is a distributed network that caches web content on edge servers instead of serving every request from a single origin. Images, CSS, JavaScript, fonts, video segments, downloads, and selected API responses can be delivered through a CDN.
When a user visits a site, the request is routed to a nearby or optimal edge location. If the content is already cached there, it is returned immediately. If not, the CDN fetches it from the origin, sends it to the user, and stores it for later requests.
What Does It Improve?
A CDN reduces latency, lowers bandwidth and compute pressure on the origin, and helps absorb traffic spikes. Many providers also offer DDoS mitigation, WAF rules, bot protection, image optimization, and modern protocol support such as HTTP/3.
Cache rules need care. Users may see stale files, or private responses may be cached publicly if headers are wrong. Static assets, public pages, and user-specific responses should therefore use different policies.
SaaS products often use CDNs for frontend assets and downloadable files. For an API, cacheable GET responses should be evaluated together with rate limits, authentication, and security controls.
Related Terms
Anycast advertises the same IP address from multiple locations and uses BGP routing to send traffic to the nearest or best network point.
API (Application Programming Interface)An API is a contract that lets software systems request approved data or actions from one another through documented endpoints.
CacheA cache stores frequently used data temporarily so applications can respond quickly without repeating expensive origin requests.
CloudflareCloudflare is a global internet platform providing DNS, CDN, security, performance, and edge compute services from one network.
Content DeliveryContent delivery serves static files, media, and pages from infrastructure close to users to improve speed, availability, and resilience.
Edge ComputingEdge computing processes data or application logic closer to users instead of sending every request to one central server.
Image OptimizationImage optimization makes pages load faster through correct sizing, modern formats, compression, responsive delivery, and loading strategy.
LatencyLatency is the time it takes for a network request to travel from source to destination and back; low latency is key to performance.
Load BalancerA load balancer distributes incoming network traffic across multiple servers to ensure high availability and performance.
SaaS (Software as a Service)SaaS delivers software by subscription through a browser or app, with hosting, updates, and operations handled by the provider.