How Apache communicate with PHP
Reference:
How does PHP interface with Apache?
https://stackoverflow.com/questions/2772400/how-does-php-interface-with-apache/2772929
How Apache communicate with PHP?
https://stackoverflow.com/questions/53039948/how-apache-communicate-with-php/53040298
Run PHP in MAC
https://stackoverflow.com/questions/19951457/double-click-and-run-the-php-script-on-mac/19951643