Which statement about CDN performance is true?

Which statement about CDN performance is true?

• A. It always reduces latency by caching dynamic content.
• B. It can increase origin server load under heavy traffic.
• C. It caches static assets at edge locations to reduce latency.
• D. It requires no origin server in any case.

Answer: (C)

Caching content at edge locations closer to users is the main driver of CDN performance. By storing copies of static assets—like images, CSS, and JavaScript—on edge servers around the world, a CDN can serve those files from a server that’s geographically near the user. This shortens the distance the data has to travel, reduces response time, and cuts down on bandwidth used at the origin. That’s why caching static assets at edge locations to reduce latency is the best description. Static assets are ideal for this approach because they don’t change with every request, so the edge can keep them for longer and still stay in sync with the origin through proper cache-control headers and TTLs. Dynamic content, which can vary per user or session, isn’t reliably cacheable in the same way, so saying it always reduces latency by caching dynamic content isn’t accurate. Some CDNs can accelerate dynamic content under certain configurations, but it isn’t a universal rule. CDNs are designed to offload work from the origin. They typically reduce origin load, not increase it, though rare cache misses can temporarily touch the origin. Finally, an origin server is usually still involved whenever content isn’t cached or when fresh content is needed, so the idea that a CDN requires no origin server in any case isn’t correct.

Caching content at edge locations closer to users is the main driver of CDN performance. By storing copies of static assets—like images, CSS, and JavaScript—on edge servers around the world, a CDN can serve those files from a server that’s geographically near the user. This shortens the distance the data has to travel, reduces response time, and cuts down on bandwidth used at the origin.

That’s why caching static assets at edge locations to reduce latency is the best description. Static assets are ideal for this approach because they don’t change with every request, so the edge can keep them for longer and still stay in sync with the origin through proper cache-control headers and TTLs.

Dynamic content, which can vary per user or session, isn’t reliably cacheable in the same way, so saying it always reduces latency by caching dynamic content isn’t accurate. Some CDNs can accelerate dynamic content under certain configurations, but it isn’t a universal rule.

CDNs are designed to offload work from the origin. They typically reduce origin load, not increase it, though rare cache misses can temporarily touch the origin.

Finally, an origin server is usually still involved whenever content isn’t cached or when fresh content is needed, so the idea that a CDN requires no origin server in any case isn’t correct.