What is cPanel's version of NGINX used for?
cPanel has designed our release of NGINX so that it serves as a caching server.
This is done by configuring NGINX as a cache and reverse proxy for each domain on the server.
This means that NGINX will listen on ports 80 and 443, and accept all of the web requests that the sites on your server receive.
If you have caching enabled for a domain (which is turned on by default) NGINX will create and use a cache of the web page which can substantially increase performance for some websites.
If the cache has expired, turned off, or for the first request of a website, NGINX will proxy the request to the backend web server. In most cases the backend web server will be Apache, but also may optionally be LiteSpeed. The backend web server will process the request and then pass the response to NGINX. NGINX will then serve the response to the client.
You may review our official documentation about NGINX on cPanel here for more detailed information:
cPanel Docs - NGINX with Reverse Proxy