The web part can be used to create an RSS feed of blog posts on your site. It uses a built-in pre-configured documents data source as a source of the blog posts. It displays a link leading to the feed, which is located at the URL of the page where the web part is placed, with a querystring parameter appended.
Help URL: http://devnet.kentico.com/docs/webparts/index.html?BlogPostsRSSFeed_overview.htm