You can get the full path of the current file using any of:

• __FILE__, a magic constant
• $_SERVER['SCRIPT_FILENAME'] (more on $_SERVER later!)

You can get the full path of the folder where the current file is in using:

• the getcwd() built-in function
• __DIR__, another magic constant
• combine __FILE__ with dirname() to get the current folder full path: dirname(__FILE__)
• use \$_SERVER['DOCUMENT_ROOT']