1、 Why use CDN (English: Content Delivery Network or Content Distribution Network, abbreviation: CDN) refers to a computer network system that connects with each other through the Internet. It uses the server closest to each user to send music, pictures, movies, applications and other files to users faster and more reliably, To provide high performance, scalability and low-cost network content delivery to users. A brief summary has the following advantages. Improve the access speed of the site (especially the site with a large number of pictures and static pages), and greatly improve the stability of the image service of the above nature site, eliminate the impact of the bottleneck caused by the interconnection between different operators, and achieve