What is the difference between $_SERVER['DOCUMENT_ROOT'] and '/temp' when specifying file paths in PHP?

When specifying file paths in PHP, $_SERVER['DOCUMENT_ROOT'] provides the absolute path to the root directory of the server, while '/temp' represents a relative path to a directory named 'temp' at the root level of the server. Using $_SERVER['DOCUMENT_ROOT'] ensures that the path is consistent across different servers, while '/temp' may not work if the directory structure changes. It is recommended to use $_SERVER['DOCUMENT_ROOT'] for specifying file paths in PHP to ensure portability and reliability.

// Using $_SERVER['DOCUMENT_ROOT'] to specify file path
$file_path = $_SERVER['DOCUMENT_ROOT'] . '/temp/file.txt';