PHP, which is a bacronym for PHP: Hypertext Preprocessor, is among the most commonly used open-source web programming languages available out there. Any website or Internet application created with PHP will run on a given web server provided that a PHP module is activated, which makes the language really universal and it is not really that surprising that there are actually a couple of million web servers that support it and hundreds of millions of PHP websites running on them. PHP is preferred over HTML because of the fact that it enables you to set up a dynamic serving website with a huge number of features. A PHP-based community site, for example, will display unique content to each user even though the URL will stay the same. In contrast, HTML sites are static and the page content can be modified only manually. Like any other software, PHP has several versions and the version that was used while creating a given website must be set up on the server in order for the site to behave properly.