Drawing settings from options panel

I’m trying to build a theme and I’m new at this so I look at available themes and try to learn things. To draw the custom css settings from an options panel one theme had something like this:

<?php if ( get_option('of_custom_css') <> "" ) {?>
<style type="text/css">
<?php echo get_option('of_custom_css'); ?>
</style>
<?php }?>

I never saw <>"" used before so I’m not sure if that’d be right if I use it?