PHP, which is a metacronym for PHP: Hypertext Preprocessor, is one of the most famous programming languages available out there. Any website or web app created using PHP will run on a given server on the condition that a PHP module is installed, which makes the language truly universal and it is not unusual that there are actually several million web servers that support it and 100s of millions of PHP-powered sites running on them. PHP is preferred over HTML because it permits you to develop an interactive site with a large number of features. A PHP-based community portal, for example, will display different web content to each visitor regardless of the fact that the URL will remain the same. In contrast, HTML sites are static and the page content can be edited only manually. Like any other software, PHP has several versions and the one that was used whilst creating a particular website must be present on the web server so that the site can run flawlessly.