How can PHP be used to separate backend and frontend functionalities for better website performance?

To separate backend and frontend functionalities for better website performance, we can use PHP to handle the backend logic and data processing separately from the frontend presentation. This separation allows for more efficient processing and better organization of code, resulting in improved performance and easier maintenance.

// backend.php

// Backend logic for processing data
function processData($data) {
    // Process data here
    return $processedData;
}
```

```php
// frontend.php

// Frontend presentation for displaying data
function displayData($data) {
    // Display data here
}