Custom CMS block displayed as a tab. You can use it to display info about returns and refunds, latest promotions etc. You can put your own content here: text, HTML, images - whatever you like. There are many similar blocks accross the store. All CMS blocks are editable from the admin panel.
Magento Community Edition is the most powerful open source e-commerce software and can be downloaded 100% for free. Developers can modify the core code, add custom features and functionality by installing extensions from Magento Connect marketplace.