RSS stands for “Rich Site Summary” or “Really Simple Syndication,” and maybe any number of other things in other contexts. But in the world of blogging, it means a subscription to the site’s feed. In other words its a way of receiving updates whenever new content is posted on a feed to which you are subscribed. This way you can look at just one aggregator or reader and be up-to-date on a whole variety of content. Google reader, Netvibes, and Bloglines are just a few such online aggregators of content.
And above is the increasingly common logo for rss subscription.