How can the action attribute in a form tag impact variable passing in PHP scripts?

The action attribute in a form tag specifies the URL where the form data should be submitted. If the action attribute is not set or set to an empty string, the form data will be submitted to the same URL where the form is located. This can impact variable passing in PHP scripts because the form data will be sent to a different URL, potentially causing issues with accessing the form data in the PHP script. To solve this issue, make sure to set the action attribute to the correct URL where the PHP script that processes the form data is located.

<form action="process_form.php" method="post">
    <!-- form fields go here -->
</form>