Your DirectoryIndex is with a part of your apache configuration. Apache doesn't ship with PHP and sometimes requires you to manually add the DirectoryIndex.
DirectoryIndex is basically apache saying "If no file is specified, I'm going to try and find one of the files in DirectoryIndex" but obviously home.php and index.html aren't there, so we need to add index.php.
Check whether your DirectoryIndex is in your httpd.conf file and add index.php
DirectoryIndex is basically apache saying "If no file is specified, I'm going to try and find one of the files in DirectoryIndex" but obviously home.php and index.html aren't there, so we need to add index.php.
Check whether your DirectoryIndex is in your httpd.conf file and add index.php