What is "RSS" and what do you use it for?

RSS is a family of Web feed formats used to publish frequently updated works – such as blog entries, news headlines, audio, and video – in a standardized format.[2] An RSS document (which is called a "feed", "web feed",[3] or "channel") includes full or summarized text, plus metadata such as publishing dates and authorship. Web feeds benefit publishers by letting them syndicate content quickly and automatically. They benefit readers who want to subscribe to timely updates from favored websites or to aggregate feeds from many sites into one place. RSS feeds can be read using software called an "RSS reader", "feed reader", or "aggregator", which can be web-based or desktop-based. A standardized XML file format allows the information to be published once and viewed by many different programs. The user subscribes to a feed by entering the feed's URI into the reader or by clicking an RSS icon in a browser that initiates the subscription process. The RSS reader checks the user's subscribed feeds regularly for new work, downloads any updates that it finds, and provides a user interface to monitor and read the feeds.

RSS is a standard format for syndicating content on the Internet. The content can be anything! Often information contained in an RSS feed is syndicated on other sites which expands its reach.

Website visitors love RSS because they choose which feeds they wish to subscribe to, if at any point they are unhapy with the content contained in the RSS feed they simply unsubscribe and no longer receive notification of feed updates.

RSS is really a win, win for both subscribers and publishers.

In order to get a better understanding of how RSS works download an RSS reader or use a web aggregator and subscribe to an RSS feed (they are usually indicated by a small orange icon).

RSS is a family of Web feed formats used to publish frequently updated works – such as blog entries, news headlines, audio, and video – in a standardized format.[2] An RSS document (which is called a "feed", "web feed",[3] or "channel") includes full or summarized text, plus metadata such as publishing dates and authorship. Web feeds benefit publishers by letting them syndicate content quickly and automatically. They benefit readers who want to subscribe to timely updates from favored websites or to aggregate feeds from many sites into one place. RSS feeds can be read using software called an "RSS reader", "feed reader", or "aggregator", which can be web-based or desktop-based. A standardized XML file format allows the information to be published once and viewed by many different programs. The user subscribes to a feed by entering the feed's URI into the reader or by clicking an RSS icon in a browser that initiates the subscription process. The RSS reader checks the user's subscribed feeds regularly for new work, downloads any updates that it finds, and provides a user interface to monitor and read the feeds.

Here's an article on it, it's one of the easier ones to understand
http://apps.doteasyblog.com/blog/?e=358&d=09/18/2007&s=RSS%20%E2%80%93%20What%20Is%20It%3F