PHP is a widely-used open source general-purpose scripting language designed specifically for use on the web. Development of PHP began in 1994 by Rasmus Lerdorf.He extended C base CGI to add the ability to work with web forms and to communicate with databases, and called this implementation "Personal Home Page/Forms Interpreter" or PHP/FI. PHP/FI could be used to build simple, dynamic web applications. Later, Lerdorf release PHP/FI as "Personal Home Page" or PHP. It now stands for PHP: Hypertext Preprocessor, which is a recursive backronym.
PHP offers many advanced features for a professional programmer to develop dynamic web applications. PHP code processed by a PHP interpreter, which is usually implemented as a web server's native module or a CGI executable. It work as a server side scripting language that executed on the server and generate result for client, but client would not know what the underlying code was. Instead of lots of commands to output HTML, PHP pages contain HTML with embedded code, which make it is extremely simple and easy for web development.
PHP interpreter is free software released under the PHP License by the Zend Engine, now produced by The PHP Group. PHP has been widely ported and can be deployed on most web servers on almost every operating system and platform at free of cost.