What is a content delivery network (CDN) and how does it improve web performance?

What is a content delivery network (CDN) and how does it improve web performance?

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

Answer: (B)

A CDN boosts web performance by bringing content closer to users through a network of edge servers. When a page requests assets like images, CSS, or scripts, the CDN serves those files from the edge server nearest the user, rather than always pulling them from the distant origin server. This shorter distance lowers latency, speeds up overall load times, and helps the site handle traffic spikes because many requests are handled at the edge instead of hitting the origin. Caching at edge locations is the core reason this improves speed. Because the edge servers store copies of frequently requested content, repeated requests can be served quickly from nearby locations. The origin server is still involved for content that isn’t cached or has expired, but the majority of typical asset delivery becomes much faster. This approach also reduces bandwidth and server load on the origin, contributing to smoother performance during high demand. The other options don’t address this primary mechanism. Compressing content on the server targets bandwidth rather than delivery speed across distance. Storing backups for disaster recovery is about reliability, not performance. Running client-side scripts to optimize rendering is about browser-side work, not how content is delivered from the network.

A CDN boosts web performance by bringing content closer to users through a network of edge servers. When a page requests assets like images, CSS, or scripts, the CDN serves those files from the edge server nearest the user, rather than always pulling them from the distant origin server. This shorter distance lowers latency, speeds up overall load times, and helps the site handle traffic spikes because many requests are handled at the edge instead of hitting the origin.

Caching at edge locations is the core reason this improves speed. Because the edge servers store copies of frequently requested content, repeated requests can be served quickly from nearby locations. The origin server is still involved for content that isn’t cached or has expired, but the majority of typical asset delivery becomes much faster. This approach also reduces bandwidth and server load on the origin, contributing to smoother performance during high demand.

The other options don’t address this primary mechanism. Compressing content on the server targets bandwidth rather than delivery speed across distance. Storing backups for disaster recovery is about reliability, not performance. Running client-side scripts to optimize rendering is about browser-side work, not how content is delivered from the network.