PHP Global Variables

Global variables (or Superglobals) in php are variables (arrays) that hold useful information about server configuration, request details, form parameters, cookies and session information.

PHP creates them automatically, you don't have to define them. Superglobals are accessible from within any files and are also visible from inside function definitions.

Here a list of them:

$_GET

$_POST

$_SESSION

$_COOKIE

$_ENV

$_FILES

$_REQUEST

$_SERVER