extention name

[joonstar]

(1) file.php
(2) file.php3


What is the difference between the extention names?

[Phantom]

In version 3 of PHP, the extension was .php3 - now it's just .php

[Eddyd84]

There is no difference between
.php, .php3, .php4, .pthml, .blah
as long as your .htaccess is set to parse files with those extemtions as php. In your .htaccess add:
AddType application/x-httpd-php .php, .php3, .icn, .blah, .codingforums

or whatever
:)