A Content Delivery Network (CDN) is a geographically distributed network of servers that delivers digital content as close as possible to the respective user. Instead of retrieving content directly from the original web server, the so-called origin server, with each request, frequently needed data can be delivered via various CDN locations.
This can shorten transmission paths, which can reduce latency, improve loading times, and relieve the origin server. CDNs are therefore used particularly for websites, online shops, streaming services, downloads, and applications with internationally distributed users.
A CDN distributes content to servers at various geographical locations. These are often located at so-called Points of Presence (PoPs).
For example, when a user accesses a website, the request is processed via a suitable CDN location. If the requested content is already in the temporary storage there, the so-called cache, it can be delivered directly.
If the content is not yet available there or is no longer current, the CDN must first retrieve it from an upstream cache layer or from the origin infrastructure. Depending on the defined cache rules, the content can then be cached for further requests.
The more optimally the CDN location is network-technically closer to the user, the shorter the transmission paths and thus the lower the latency can be.
A Content Delivery Network can offer various advantages, especially with high access numbers or geographically distributed users:
Many CDN providers also combine their infrastructure with security features such as DDoS protection or Web Application Firewalls. However, these functions are not fundamentally part of every CDN.
The servers through which a CDN delivers content as close as possible to the user are often referred to as edge servers. They are located at geographically distributed network locations or Points of Presence.
However, how quickly data actually reaches the user does not depend solely on geographical distance. Routing, peering, bandwidth, and the utilization of the involved networks also play an important role.
A powerful backbone and good connections between different networks therefore also contribute to short transmission paths and low latencies. IP transit also plays an important role in connecting and forwarding data between networks.
A CDN is particularly useful when content is accessed by many users, from different regions, or with high data volumes.
Typical areas of application include:
Whether a CDN actually provides a significant speed advantage depends on the specific application, the location of the origin server, the geographical distribution of users, and the existing network infrastructure.
CDN stands for Content Delivery Network. It refers to a network of geographically distributed servers that can deliver digital content as close as possible to the respective user.
A CDN server is a server within a Content Delivery Network. It can cache content and deliver it to users without every request having to be forwarded directly to the origin server.
A CDN can reduce a website’s loading time, especially if users are far from the original server. However, the actual effect depends, among other things, on the website, cache configuration, routing, and the existing network infrastructure.
The origin server is the original source of a website or application. The CDN complements this server with a distributed infrastructure and can cache and deliver suitable content at various locations.
