PHP, which is a recursive initialism for PHP: Hypertext Preprocessor, is among the most popular general-purpose programming languages that are available out there. Any website or web-based application built on PHP will run on a given server as long as a PHP module is installed, which renders the language truly universal and it is hardly unusual that there are actually a few million servers that support it and hundreds of millions of PHP-powered sites running on them. What makes PHP preferred over HTML is the fact that it enables you to set up a dynamic website with a plethora of different options. A PHP-based community site, for example, will display unique web content to each visitor although the URL will remain unchanged. In contrast, HTML-based websites are static and the page content itself can be edited only manually. Like any other software, PHP has several versions and the one that was used while building a certain website must be enabled on the web server in order for the site to work faultlessly.