Super Global Variable

In php there eight variables. These eight variables are fixed, constant and can't be changed. This variable is started with $_. For several reasons, they are known as super global variables. Different variables have different duty to do. Some works with file, some works with request and some works to send data to sever. Let’s see the below table for better clearance.

Syntax Usage
$_FILES Works with File(Upload, Check Type)
$_GET Receives Data
$_POST Sends Data to Server
$_REQUEST Responds to The Request
$_SESSION Set Session for User Access
$_COOKIE Set Cookie for User Identification
$_SERVER Request Server and Get Server Info

$_ENV is used not so much but has usage also.