Wikipedia
Httpd.conf
httpd.conf is a configuration file which is used by the Apache HTTP Server. It is the file which apache server looks at for its different configuration properties . Properties can be directly edited from the file using super user permissions.
The httpd.conf file can be located on any Unix-based system that complies with the Filesystem Hierarchy Standard under the following path: /etc/httpd/httpd.conf.
This file, httpd.conf was once used in Microsoft's Internet Information Services (IIS).