How can the separation of HTML and PHP code improve the readability and maintainability of a project?

Separating HTML and PHP code can improve readability and maintainability by making it easier to understand the structure of the code, allowing for clearer separation of concerns, and enabling easier collaboration between front-end and back-end developers. This separation also makes it simpler to make changes to the HTML without affecting the PHP logic, and vice versa.

<?php
// PHP logic here

?>

<!DOCTYPE html>
<html>
<head>
    <title>Example</title>
</head>
<body>
    <h1>Welcome</h1>
    <p><?php echo "Hello, world!"; ?></p>
</body>
</html>