Content Delivery Network (CDN)

A content delivery network (CDN) is a group of servers spread across many locations that store copies of a website's content close to users, so pages and files load faster and the origin server carries less load.

How does a CDN work?

A CDN caches copies of a site's static content, such as images, scripts, and stylesheets, on edge servers in many regions. When a user requests the content, it is served from a nearby edge server instead of the distant origin, which cuts the distance the data must travel.

Why do sites use a CDN?

Serving content from nearby edge servers reduces delay and speeds up load times, while offloading traffic from the origin server improves reliability and helps absorb sudden spikes. Many CDNs also add security features such as filtering malicious traffic.

What content can a CDN cache?

CDNs are best at caching static assets that do not change per user, such as images, fonts, video, scripts, and stylesheets. Dynamic, user-specific responses are usually generated at the origin, though some CDNs can cache parts of them too.

Frequently asked questions

Does a CDN host my whole website?

Not necessarily. A CDN typically caches and serves copies of your content from edge servers, while your origin server still holds the original site and handles dynamic requests.

Does a CDN make a website faster?

Usually yes, because it serves content from a server near the user and reduces the distance and load, which lowers delay and speeds up page loads.


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