PHP is a server-side scripting language used by web developers to create functionality and processes that run on the server in response to a web request. PHP is a recursive acronym that stands for PHP Hypertext Preprocessor. You can use PHP to respond to a request from a webpage or in conjunction with AJAX to create real-time request and response procedures.
When writing a PHP file the extension should be ‘.php’ and the code must be encased within PHP tags. The opening PHP tag is ‘<?php’ and the closing tag is ‘?>’, all of your PHP code must be contained within these tags. You can create standalone PHP files to handle requests or for processes that are done entirely on the server-side, or even to structure your server-side data model.
<?php echo "Hello World"; ?>
<body> <?php echo "Hello World"; ?> </body>