What is a CDN?
A CDN, or content delivery network, is a group of servers spread around the world that cache copies of your content close to users. When someone loads your site, images and files come from a nearby server instead of a distant one, which makes the site much faster and reduces load on your main server.
- A CDN is a network of servers that cache content close to users.
- It reduces latency and offloads traffic from the origin server.
- It is commonly used for images, videos, scripts, and other static assets.
How it helps
- Faster loading: content is served from a server near the user.
- Less load: your main server handles fewer direct requests.
- More reliable: if one edge server is busy, others can serve.
Say your server is in the US and a user is in India. Without a CDN, every image travels across the world. With a CDN, a cached copy sits on a server in India, so it loads quickly.
Mention that CDNs are mainly for static content like images, CSS, and videos. Noting that dynamic, personalised data usually is not cached shows you understand what a CDN is good for.
Frequently asked questions
How does a CDN speed up a website?
It serves cached content from a server near the user instead of the distant origin, which cuts latency and speeds up page loads.
What content should you put on a CDN?
Static assets like images, CSS, JavaScript, and videos benefit most, since they rarely change and can be cached and reused across many users.
Common follow up questions
Related interview questions
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