What is the significance of the __FILE__ constant in PHP when dealing with file paths?

The __FILE__ constant in PHP represents the full path and filename of the current script. It is useful when dealing with file paths because it allows you to reference files relative to the current script's location, making your code more portable and easier to maintain.

// Example usage of __FILE__ constant to include a file relative to the current script
include dirname(__FILE__) . '/path/to/file.php';