session problem

working on a bought login script and this line I can't figure out the meaning
PHP Code:
<?php ob_start(); ?>
<?php include_once('classes/translate.class.php'); ?>
<?php if (!isset($_SESSION)) session_start(); ?> <—- this logic is not making sense to me.
It says if $_SESSION is not set then start session. My question is if $_SESSION is not set why would you want to start a session.. Shouldn't I start/ continue a session only if that is set.. Other wise any one would be able to log into my…
session problem

See original post by ameerulislam43