As mentioned earlier, standard HTTP modules are built into Nginx by default unless you explicitly disable them. As the name suggests, these modules provide standard HTTP functionality to the web server. We will now have a look at some of the important standard HTTP modules.
The core module deals with the core HTTP features. This includes the protocol version, HTTP keepalive, location (different configurations based on URI), documents' roots, and so on. There are over 74 configuration directives and over 30 environment variables related to the HTTP Core module. We will discuss the most important ones briefly.
The following is an explanation of some of the key core module directives. This list is not exhaustive, and you can find the full list at http://wiki.nginx.org/HttpCoreModule.