"News Feed Ads", also called "Sponsored Stories", "Boosted Posts", typically exist on social media platforms that offer a steady stream of information updates ("news feed") in regulated formats (i.e. in similar sized small boxes with a uniform style). Those advertisements are intertwined with non-promoted news that the users are reading through. Those advertisements can be of any content, such as promoting a website, a fan page, an app, or a product.
Structured data21 is code that you can add to your sites' pages to describe your content to search engines, so they can better understand what's on your pages. Search engines can use this understanding to display your content in useful (and eye-catching!) ways in search results. That, in turn, can help you attract just the right kind of customers for your business.