CDN
CDN stands for Content Delivery Network. It refers to a large network of servers that host duplicate content to speed up download speeds. These duplicates are called ‘caches’. There are many different CDN providers, depending on what you’re hosting.
Caches make your content easier and faster to access
Let’s imagine you host a video online. If you simply put it on your own machine, everyone would need to download your video from that one computer. This would have two problems. First, if too many people try to download your video at once, you’d have a bottleneck (and your computer could crash). Second, some people might be on the other side of the world, so the download could be quite slow.
A CDN creates copies of your video and hosts these all over the world. Instead of downloading from your machine, people can download from the closest available cache.