Alibaba Cloud CDN distinguishes between two types of content: static content, which is cacheable, and dynamic content, which is not. Understanding the difference helps you choose the right acceleration strategy for your website or application.
Static content
Static content is files that CDN can cache and serve without modification — the same file is returned for every request. Static content is also known as static resources. Typical examples include images, videos, HTML documents, CSS stylesheets, JavaScript files, software installation packages, APK files, and compressed archives.
Alibaba Cloud CDN caches static content from your origin server on CDN nodes. When a user requests that content, CDN serves it directly from the nearest node — no round trip to the origin server required. This reduces load on your origin server and speeds up delivery for users worldwide.
Dynamic content
Dynamic content is generated on the fly in response to each individual request. Dynamic content is also known as dynamic resources. Because the server produces content based on user behavior, query parameters, or real-time data, no two responses are identical. Examples include pages rendered by ASP, JSP, PHP, Perl, and CGI scripts, as well as API requests and database queries.
CDN nodes cannot cache dynamic content. Each request is forwarded to your origin server, which generates and returns the response. As a result, standard CDN acceleration does not apply to dynamic content.
Accelerate dynamic content with DCDN
For applications with significant dynamic content and high API request volumes, use Dynamic Route for CDN (DCDN). DCDN accelerates both content types:
Alibaba Cloud CDN accelerates static content by caching it on CDN nodes.
DCDN accelerates dynamic content through routing and transmission optimization.