Content Delivery Network
A Content Delivery Network (CDN) is a network of servers in many locations that maintains copies of your static files. When someone visits your site, images, fonts, and scripts are retrieved from the nearest location instead of the original server.
The advantage comes from distance. Each request to Sydney and back takes approximately 300 milliseconds due to physical limitations, regardless of your server speed. If the file is located in Sydney instead, it takes only 20 milliseconds.
This explains who benefits: websites with an international audience, those with a lot of images, and those experiencing sudden spikes in traffic. A small business in Düsseldorf, whose visitors almost all come from the surrounding area, gains little from having its server located in Germany anyway. For them, caching and low-resolution images are far more effective.
Data privacy must also be considered: A CDN processes the IP addresses of your visitors. For providers outside the EU, this must be included in the privacy policy and weighed against other factors.
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