index.php
File suffix .php means PHP sections are interpreted.
Directory Index
By default, with no .htaccess directive, the default page for a folder is defined as
DirectoryIndex index.php index.cgi index.html
Filename Suffix
The suffix lets Apache know how to preprocess the file.
-
index.cgi
By default a2hosting created a cgi-bin directory when I created the subdomain,
but the script runs from any folder.
-
index.php
This file is suffixed with .php, so php sections are interpreted.
Most likely this is implemented with mod_php which allows for mixed html and php.
-
index.html
Straight HMTL. PHP sections are ignored.