Which statement best describes the function of a CDN's edge servers?

Which statement best describes the function of a CDN's edge servers?

• A. A CDN caches content at distributed edge servers to reduce latency and improve load times.
• B. A CDN stores backups in a distant data center for disaster recovery.
• C. A CDN runs client-side scripts to optimize rendering.
• D. A CDN compresses content on the server to reduce bandwidth only.

Answer: (A)

Caching content at distributed edge servers to bring data closer to users reduces latency and improves load times. Edge servers sit in many locations around the world and hold copies of static assets (like images, CSS, and JavaScript) and sometimes responses from the origin. When someone requests a resource, the CDN serves it from the nearest edge server, cutting the distance data travels and shortening the round-trip time. This proximity speeds up delivery and lowers the load on the origin server because many requests are served from the cache rather than traveling all the way back to the origin. Caches are refreshed or invalidated using mechanisms like TTL and cache-control headers so updates propagate efficiently.

Backups in distant data centers are about disaster recovery, not delivering content quickly to end users. Running client-side scripts isn’t the primary role of edge servers, and while some CDNs can apply server-side optimizations, edge caching is the core function. Compression on the server can help bandwidth, but it doesn’t define the main purpose of edge servers, which is to cache and distribute content to reduce latency.