PHP (Hypertext Preprocessor) is a server-side scripting language which is used for web application development.PHP was created by Rasmus Lerdorf in 1994. PHP is open-source: Open source means that PHP is a free programming language, so you don’t have to worry about additional costs to build your web application. It is very easy language to learn and develope the web applications. PHP can easily embade with the HTML code.PHP file must be save with `.php` extension.