Introduction to RSS
Really Simple Syndication, or RSS, is an XML document format that notifies users when you've updated your website. By providing an RSS feed, you free your users from the tedium of having to constantly check your website for updates by allowing them to aggregate updates from multiple sources, view them all in one place, and be notified of updates when they occur.
The main benefit of RSS over a newsletter is that with a newsletter, you have to strike a careful balance between sending updates too frequently and possibly annoying some of your users by flooding their inboxes with mail, or not sending newsletters out frequently enough. With RSS, users check on their subscribed feeds as often as they like.
If you update your website manually, maintaining an RSS feed may appear to be a tedious task, since you have to format the same content twice; however, many popular blogging and content management systems will generate RSS feeds for you automatically whenever you update your website. RSS is also a popular method of Podcasting, a term used to describe regularly publishing audio or video content (like the Internet equivalent of a Tivo or similar device for a television or radio show) to be downloaded automatically by users and then transferred to their portable multimedia players for viewing anywhere at their convenience.
RSS aggregators can be native applications, programs which run on your personal computer like any other software, like RSSOwl, or web-based software like NewsNinja which are viewed through a web browser.