I was trying to Use a PHP class, and in the instructions to use it was mentioned separately for "PHP with autoloading enabled" and "PHP w/o Autoloading".
How Do I know if my version of PHP which is 5.4+ uses Autoloading or not ?
Here you can read about autoload.
To find out if your framework or set of classes use autoload you can search for: __autoload or spl_autoload_register
Or just search for _autoload to find both mentions.
Search your code base for __autoload. If you find anything you are using (or your framework is) auto-loading, otherwise you are not.