title: what's those line meaning in magento?
body: <pre><code>&lt;?php foreach ($this-&gt;getChildGroup('detailed_info', 'getChildHtml') as $alias =&gt; $html):?&gt;
      &lt;div class="box-collateral &lt;?php echo "box-{$alias}"?&gt;"&gt;
          &lt;?php if ($title = $this-&gt;getChildData($alias, 'title')):?&gt;
          &lt;h2&gt;&lt;span&gt;&lt;?php echo $this-&gt;escapeHtml($title); ?&gt;&lt;/span&gt;&lt;/h2&gt;
          &lt;?php endif;?&gt;
          &lt;?php echo $html; ?&gt;
      &lt;/div&gt;
  &lt;?php endforeach;?&gt;
      &lt;?php echo $this-&gt;getChildHtml('product_additional_data') ?&gt;
  </code></pre>
  
  <p>what's those line meaning in magento?</p>