The PHP_SELF predefined variable contains the filename and path of the PHP script that is currently being executed.
Current page: /infost440/a3/predefined.php
The SERVER_NAME predefined variable contains the name of the server where the PHP script is running.
Server name: emathies.soisweb.uwm.edu
Predefined variables are variables that PHP automatically provides to a program. They contain useful information about the server, browser, request, and other parts of the web environment. Many predefined variables are called superglobals because they can be accessed from different scopes in a PHP program. The examples above use the $_SERVER superglobal to display information about the current page and the server.