title: what is JHtml::_?
body: <p>following is the code i am trying to understand of joomla MVC compenet development</p>
  
  <pre><code>protected function getOptions() 
      {
              $db = JFactory::getDBO();
              $query = $db-&gt;getQuery(true);
              $query-&gt;select('id,greeting');
              $query-&gt;from('#__helloworld');
              $db-&gt;setQuery((string)$query);
              $messages = $db-&gt;loadObjectList();
              $options = array();
              if ($messages)
              {
                      foreach($messages as $message) 
                      {
                              $options[] = JHtml::_('select.option', $message-&gt;id, $message-&gt;greeting);
                      }
              }
              $options = array_merge(parent::getOptions(), $options);
              return $options;
      }
  </code></pre>
  
  <p>i am unable to understand following statement</p>
  
  <pre><code>JHtml::_('select.option', $message-&gt;id, $message-&gt;greeting);
  </code></pre>
  
  <p>and what is the basic purpose of JHTML class of joomla</p>