the difference between sql_autoload_register and???__autoload? [duplicate]

the difference between sql_autoload_register and???__autoload? [duplicate]

References

Reference NO 1

http://php.net/manual/en/function.spl-autoload-register.php

Reference NO 2

http://dissectionbydavid.wordpress.com/2010/11/03/php-spl-autoload-vs-__autoload/

Reference NO 3

http://www.sitepoint.com/autoloading-and-the-psr-0-standard/

Reference NO 4

http://bhardwajabhi.wordpress.com/2013/04/06/what-is-the-difference-bw-__autoload-and-spl_autoload_register/

Reference NO 5

http://stackoverflow.com/questions/6946244/splenum-does-not-autoload-in-apache-works-in-cli

Reference NO 6

http://stackoverflow.com/questions/12828186/can-psr-0-class-autoloader-load-pear-library

Reference NO 7

http://net.tutsplus.com/tutorials/php/6-codeigniter-hacks-for-the-masters/

Reference NO 8

https://github.com/krakjoe/pthreads/issues/153