If you are including a link to a css file in your Joomla template index.php file, you want the URL for the css to be generated automatically rather than hard coded. If you ever need to move the site to a different location this code will make sure that the css file is still properly located and loaded. This code generates the path dynamically.

<link rel="stylesheet" href="/<?php echo $this->baseurl ?>/templates/<?php echo $this->template ?>/css/template.css" type="text/css" />