A RSS feed is a system used to distribute frequently-updated content, such as blog posts; rather than visiting a blog directly, readers can subscribe to its RSS feed using a feed reader and receive updates as soon as new content is published. WordPress automatically creates a RSS feed for your entire blog.
Primary Blog Feed
Your WordPress blog's RSS feed can be accessed by adding "/feed/" to your blog's address. For example, if your blog is located at "http://myblog.wordpress.com/", the RSS feed containing all your blog posts will be at "http://myblog.wordpress.com/feed/", while if your blog has its own domain at "http://www.myblog.com/" the RSS feed will be at "http://www.myblog.com/feed/"
In addition to the main blog feed, WordPress also offers feeds for specific categories, tags and authors. The location of these feeds is similar to that of the primary blog feed. Feeds for categories and tags can be reached by appending "/category/NAME/feed/" and "/tag/NAME/feed/" respectively, replacing "NAME" with the name of the category or tag of interest; similarly, the feed for posts written by a specific author can be found at "/author/AUTHORNAME/feed/"
WordPress also offers RSS feeds for all the comments made on each blog, as well as for comments left on each specific post within a blog. The blog-wide comment feed can be reached by appending "/comments/feed/" to your blog's address; to reach the feed for a specific post, on the other hand, you must append "/feed/" to the address of the post itself.
If you do not want your blog to have a RSS feed, you can turn it off by marking your blog as "private" in the "Privacy" menu, found under "Settings" in the menu on the left of your dashboard. By editing the options found in the "Reading" menu, you can also adjust how many posts your main RSS feed will send out at once, as well as control whether it displays summaries or full text and whether any additional information, such as categories, tags and comments, is displayed at the bottom of each post within the feed.