Header Help on Default/All Templates!!

Hi i am cleaning up my code and was wondering what does:

<meta name=”generator” content=”WordPress <?php bloginfo(‘version’); ?>” /> <!– leave this for stats –>

and:

<?php
// Checks to see whether it needs a sidebar or not
if ( !$withcomments && !is_single() ) {
?>
<?php } else { // No sidebar ?>
<?php } ?>

</style>

do? Leave this for stats? Meaning what stats? and what about the second part i know it is commented and i am stupid but i cannot figure it out!!