How to modify a piece of code coming from ‘detailed_info’ group?

I have a piece of code that is calling: getChildGroup(‘detailed_info’, ‘getChildHtml’).

I need to add new data but I don’t have a clear picture of where that comes from. Apparently, that’s a common piece of code in Magento, but still, couldn’t find the answer online.

This is the code…

<?php if ($  detailedInfoGroup = $  this->getChildGroup('detailed_info', 'getChildHtml')):?>          <h4><?php echo $  this->__('Details') ?></h4>          <?php $  itemprop = 'itemprop="description"' ?>          <?php foreach ($  detailedInfoGroup as $  alias => $  html): ?>                <div <?php echo $  this->__($  itemprop); ?>class="info-content"><?php echo $  html ?></div>                <?php $  itemprop = ''; ?>          <?php endforeach;?> <?php endif; ?> 

And this is an image so you know where I need to add the new data.

newdata

Where is the content coming from?

Thank you ver much!