Why is it not feasible to use PHP to continuously monitor and track users on a website due to the stateless nature of HTTP protocol?

PHP is not suitable for continuously monitoring and tracking users on a website due to the stateless nature of the HTTP protocol. To overcome this limitation, you can use a combination of PHP and JavaScript to implement real-time tracking. By using JavaScript to send periodic AJAX requests to the server, you can keep track of user activity without relying solely on PHP.

```php
// PHP code to handle AJAX requests for tracking user activity
if(isset($_POST['user_id'])){
    $user_id = $_POST['user_id'];
    
    // Update user's last activity timestamp in the database
    // This can be used to track user activity in real-time
    // You can also log user actions or perform other tracking tasks here
}
```
This PHP code snippet demonstrates how you can handle AJAX requests sent by JavaScript to track user activity in real-time. By updating the user's last activity timestamp in the database, you can monitor user interactions on the website.