PHP 5 is the latest version of PHP: Hypertext Preprocessor, a widely used web scripting language. PHP is used by software engineers and developers when programming the backend of both small and large websites. It allows websites to have dynamic content and interactive functionality. For example, a search engine or a contact form would be written in PHP. If the website’s owner needed to store user submitted data to a database for later analysis, PHP code would be written to connect the user-facing side of the website to the actual database server, such as MySQL.