PHP provides a large number of predefined variables or built-in variables to all scripts:
$GLOBALS: References all variables available in global scope.$_SERVER: Server and execution environment information.$_GET: HTTP GET variables.$_POST: HTTP POST variables.$_FILES: HTTP File Upload variables.$_REQUEST: HTTP Request variables.$_SESSION: Session variables.$_ENV: Environment variables.$_COOKIE: HTTP Cookies.
These predefined variables in PHP are "superglobals", or automatic global variables,
which means they are available in all scopes throughout a script.
There is no need to do global $variable; to access them within functions or methods.