What is Autoloading; How do you use spl_autoload, __autoload and spl_autoload_register?

I am learning advanced PHP standards and trying to implement new and useful methods. Earlier I was using `__autoload` just to escape including multiple files on each page, but recently I have seen a tip on [`__autoload manual`][1] > **spl_autoload_register()** provides a more flexible alternative for > autoloading classes. For this reason, using **__autoload()** is > discouraged and may be deprecated or removed in the future. but I really can't figure out how to implement [`spl_autoload`][2] and [`spl_autoload_register`][3] [1]: https://www.php.net/__autoload [2]: http://www.php.net/manual/en/function.spl-autoload.php [3]: http://www.php.net/manual/en/function.spl-autoload-register.php