What are some alternative methods in PHP to pass variables between pages without relying on URL parameters?

When passing variables between pages in PHP, relying solely on URL parameters can pose security risks and limit the amount of data that can be passed. An alternative method is to use sessions to store and retrieve variables across multiple pages. Sessions provide a more secure and flexible way to pass data between pages without exposing sensitive information in the URL.

// Start the session
session_start();

// Set a variable in the session
$_SESSION['username'] = 'john_doe';

// Retrieve the variable on another page
session_start();
echo $_SESSION['username'];