RSS, Really Simple Syndication or Rich Site Summary, is a format for delivering web content. Many news sites, blogs and online publishers syndicate their content as an RSS Feed to whoever wants it. Web sites will make a feed, or channel, available and users can regularly receive the most recent posted to the site. Most often, people will do this with an aggregator, a program that manages a number of lists and presents them in a single interface. Feeds contain a list of items or entries, each of which is identified by a link. Each item can have any amount of other metadata associated with it as well.
For courses, RSS feeds allow you to quickly post updates and allow students to subscribe to your announcements via RSS. With the feed, students, parents, and teachers can stay up to date on the latest news and announcements for the class.
Want to know more? RSS Tutorial
RSS in Plain English