How can PHP templates be customized to display different navigation options based on user login status, and what changes need to be made in the template files?

To customize PHP templates to display different navigation options based on user login status, you can use conditional statements to check if the user is logged in or not. Within the template file, you can use PHP code to determine which navigation options to display based on the user's login status.

<?php
if (isset($_SESSION['user_id'])) {
    // Display navigation options for logged in users
    echo '<a href="profile.php">Profile</a>';
    echo '<a href="logout.php">Logout</a>';
} else {
    // Display navigation options for non-logged in users
    echo '<a href="login.php">Login</a>';
    echo '<a href="register.php">Register</a>';
}
?>