How can a PHP variable be passed to a script for processing?

To pass a PHP variable to a script for processing, you can use either GET or POST methods. With GET, you can append the variable to the URL as a query parameter, while with POST, you can send the variable as part of a form submission. The script can then access the variable using $_GET or $_POST superglobals.

```php
// Example using GET method
$variable = "value";
$url = "process.php?var=" . urlencode($variable);
header("Location: $url");

// Example using POST method
<form action="process.php" method="post">
    <input type="hidden" name="var" value="<?php echo $variable; ?>">
    <input type="submit" value="Submit">
</form>
```

In the above code snippets, the PHP variable "value" is passed to a script named "process.php" for processing using both GET and POST methods.