How to Distinguish the Scope of Superglobals in PHP

The superglobals in PHP are:

• $GLOBALS
• $_SERVER
• $_GET
• $_POST
• $_FILES
• $_COOKIE
• $_SESSION
• $_REQUEST
• $_ENV

Don't be confused by the name of superglobals, their scopes vary from one to another:

• $GLOBALS

The scope can be across scripts including functions and methods, but it must be within the same web page.

• $_SERVER

The scope is the same as $GLOBALS.

• $_GET

The scope is the same as $GLOBALS.

• $_POST

The scope is the same as $GLOBALS.

• $_FILES

The scope is the same as $_POST.

• $_COOKIE

The scope can be across pages, sessions, instances until expired, but it must be within the same browser.

• $_SESSION

The scope can be across pages, but it must be within the same session.

• $_ENV

The scope can be across pages, sessions, and instances, but it must be within the same shell.