RSS is short for Really Simple Syndication. It's a way that ATP can provide you with meeting notifications, in a format you can use in a few different ways. An RSS file is a type of XML document containing summaries, links, and other information that is read by an RSS reader (called an "aggregator") or used to post the content to other sites (most commonly on blogs).
ATP recommends using an RSS aggregator so you can receive regularly updated information about our meetings. An RSS aggregator is a way to regularly get updates from many web sites using their RSS feeds, not just ATP.
Once you decide what RSS aggregator or reader you will use, just add the link above to your list of subscribed feeds.