File type: Hypertext Preprocessor
The PHP file extension is used in Web pages containing PHP code. These Web pages also include PHP functions capable of processing online forms, getting the time and date, or accessing information directly from a database.
One example of such database is MySQL database. The PHP code contained in the Web page is parsed or processed using a PHP engine within the Web server that dynamically and effectively generates HTML. The generated HTML contains the Web page content.
The HTML is then sent to the Web browser. Thus, the users do not really see the actual PHP code included in the Web page even if they are viewing the Web page source.