Some content on a website does not change and therefore should be served up either directly through the web server or a content delivery network (CDN). Examples include JavaScript, image, and CSS files.
A CDN is a third party that serves your static files. Amazon CloudFront, Akamai, and Rackspace Cloud Files are examples of CDNs. The purpose of a CDN is to remove the load of static file requests from web servers that are handling dynamic web content. For example, if you have an nginx server that handles both static files and acts as a front for a Green Unicorn WSGI server on a 512 megabyte virtual private server, the nginx server will run into resource constraints under heavy traffic. A CDN can remove the need to serve static assets from that nginx server so it can purely act as a pass through for requests to the Green Unicorn WSGI server.
CDNs distribute request load globally by using data centers in different locations.
Using Amazon S3 to host your Django static files
CDNs fail, but your scripts don't have to
django-storages is a Django library for managing static and media files on services such as Amazon S3 and other content delivery networks.