A PHTML file is a web page file containing PHP code. It's essentially an HTML file with embedded PHP scripts. The server's PHP engine processes the PHP code within the PHTML file before sending the resulting HTML to the user's web browser. This allows for dynamic content generation, database interaction, user authentication, and other server-side functionalities. PHTML files are commonly used in web development to create dynamic websites and web applications. The PHP code is typically enclosed within special tags (<?php ... ?>), which the PHP interpreter recognizes and executes. The output of the PHP code is then inserted into the HTML structure of the page. This allows developers to combine the presentation capabilities of HTML with the powerful server-side scripting capabilities of PHP. PHTML files are often used in conjunction with databases to retrieve and display data dynamically. They can also be used to handle user input, process forms, and manage sessions. Because the PHP code is executed on the server, the user's browser only receives the final HTML output, enhancing security and preventing client-side manipulation of the server-side logic.