CGI PHP vs. FastCGI vs. mod_php vs. application server?

greeting all, As far as I know, there are different ways to write a PHP application: - CGI, ie. the usual way : some PHP code in web pages, and the PHP interpreter is loaded each time a PHP page is called - FastCGI : apparently, the interpreter is loaded at boot time; the application itself might also be compiled and loaded once - mod_php : same as FastCGI? - application server : the application is compiled and loaded once; the application can either have its own web server, or use a web server as front end, and only handle its own part Any tips much appreciated, thank you. -- Saeed Ahmed Junior Software engineer Codemate Ltd <http://www.codemate.com>. My Blog: saeedahmed.net