The CDN Webstorage simply stores website static content and it will be replicated across the world at the PoP (Points of Presence). You would upload the content which you would desire, typically this would be large images or even photographic content. This will only put the single files to the CDN.
Here is an example of an link on the CDN, the image content will be loaded from the CDN, whilst the rest of the website will be loaded from the hosting source.
This image is from: