CDN is a network of servers that distributes content from an origin server to other servers located in different countries. The content is being cached on other local servers, what increases network performance and uptime. Simply said, the cached content is closer to visitors in some countries, so it can be loaded faster.
Beacuse of that, the efficiency of content delivery network depends on:
- Location of your origin server and location of your main visitor groups. If your main visitor groups are far from the origin server, then CDN can give a solid boost to a website's loading time.
- Amount of content on the website. If there is a lot of content that can be cached (images, videos etc), then loading time can be improved significantly.