nginx caches js, css, images and other information. What is the implementation principle?

Question

nginx caches js, css, pictures and other information. What is the implementation principle?

Answer 1

http://nginx.org/cn/docs/http/ngx_http_proxy_module.html
For example, there is a Tomcat server behind Nginx, and the project is deployed on the Tomcat server. Nginx forwards all requests to the Tomcat server through proxy_pass, and Tomcat returns data to Nginx. If Nginx is configured with proxy_cache, Nginx will return the js/js returned by Tomcat according to the configuration. css/img is cached in the file system (proxy_cache_path) of the server where Nginx is located.