Alibaba Cloud CDN is used to speed up file delivery. When receiving an access request, an Alibaba Cloud CDN node passively retrieves the requested content from the origin site, caches a copy of the retrieved content, and at the same time returns the content to the user. The Alibaba Cloud CDN node will return the cached content during subsequent access to the same resource.
A mirror site stores all the data of a website locally. When receiving an access request, the mirror site directly pushes the requested content to the user, without the need to retrieve data from the origin site.