What are the advantages and disadvantages of using an iframe versus include() for displaying content in PHP?

When deciding between using an iframe or include() to display content in PHP, it is important to consider the advantages and disadvantages of each method. Using an iframe allows for more flexibility in terms of displaying external content from different sources, but it may also introduce security risks if not handled properly. On the other hand, using include() is more secure as it only includes content from within the same server, but it may limit the flexibility in terms of displaying external content.

// Using include() to display content
<?php
    include('content.php');
?>
```

```php
// Using an iframe to display content
<iframe src="content.php"></iframe>