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Beginner 1 minute
CDN
A content delivery network places copies of content at edge locations around the world. A user's request can be answered by a nearby edge instead of traveling to the origin server. CDNs are especially useful for images, scripts, stylesheets, video segments, and cacheable API responses. They reduce distance and origin load, but content freshness and cache rules still matter.
Key idea
Move bytes closer to users so the origin does less work and the network path is shorter.
See it in one picture
Follow the arrowsUser
Edge
Edge
Origin
Content takes the shorter route
Real-world example
A portfolio's images and JavaScript bundles can be cached at edge locations. Someone in Singapore downloads them from a nearby point of presence instead of the origin server in Europe.
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