$_SESSION

(PHP 4 >= 4.1.0, PHP 5, PHP 7)

Session variables

An associative array containing session variables available to the current script. See the Session functions documentation for more information on how this is used.

$HTTP_SESSION_VARS contains the same initial information, but is not a superglobal. (Note that $HTTP_SESSION_VARS and $_SESSION are different variables and that PHP handles them as such)

Changelog:

4.1.0

Introduced $_SESSION that deprecated $HTTP_SESSION_VARS.

Notes:

This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. There is no need to do global $variable; to access it within functions or methods.