PHP, which is a metacronym for PHP: Hypertext Preprocessor, is one of the most widely used open-source server-side scripting languages available out there. Any website or web app created with PHP will run on a given web server on the condition that a PHP module is enabled, which makes the language really universal and it’s barely surprising that there are actually a few million servers that support it and 100s of millions of PHP sites running on them. PHP is preferred over HTML due to the fact that it allows you to set up a dynamic serving website with many different options. A PHP-based social networking website, for example, will serve unique content to each user regardless of the fact that the page URL won’t change. In comparison, HTML-based websites are static and the page content can be modified only manually. Just like any other software program, PHP has different versions and the one that was used while building a particular website must be enabled on the web server in order for the site to run correctly.