Learn in the textbookSystems for Finance and Social Infrastructure
DefinitionA CDN (Content Delivery Network, コンテンツ配信ネットワーク) copies web content such as images and videos onto cache servers (キャッシュサーバ) in many locations and serves it from a server near the user.
ExplanationThe server that holds the original content is the origin server (オリジンサーバ). Because a nearby cache server answers each request, content arrives sooner and traffic does not pile up on the origin server. When a cache server lacks the requested content, it fetches it from the origin server, passes it to the user and stores it for the next request.
AnalogyIt is like stocking a head store's goods in branches everywhere so customers can pick them up at the nearest one.
Memory hookShort for Content Delivery Network; delivery is the same word as in parcel delivery, so it is a network that delivers content.