What is RSS?
RSS is an XML formatted file that is used to syndicate website content. RSS has one of two definitions depending upon who you ask. Really Simple Syndication or Rich Site Summary. RSS files typically supply summaries of web content with links to the full versions of the content. These files are generally called Feeds.
Why use RSS?
For a comsumer, RSS is a way of automatically grabbing updated content from frequently visited sites. If you read more than 20 websites regularly then RSS is right for you. Instead of browsing 20 sites a day you check your feed reader to see who has updated and only visit the sites that have new content - provided the sites you read make content available by RSS. This allows you to either save time spent reading or to find more sites to read.
Since most feed readers download and cache the content you do not have to be connected to read updates that you have already downloaded. Because of this some feed readers allow you to save articles as well for further reference. Most readers will keep a history of read articles so you can go back and find a previously read article if needed. Without actually saving an article the old articles will eventually be purged from the history.
How do I use an RSS Feed?
RSS feeds are read by programs called aggregators or feed readers. An aggregator can be a stand alone program, a web browser add on, a web service, or integrated into a web browser. Aggregators check RSS subscriptions on set intervals and download updated content when it becomes available. The interval can be set by the RSS feed or by the aggregator if the feed does not specify the interval.
There are various ways that websites display the links to their RSS feeds. Sites that have available feeds will sometimes have buttons with XML or RSS in them to mark links to their feeds. Sometimes the sites will be set up to aid RSS aware browsers that a feed is enabled for subscription. In this case the browser will notify the user is some way that a feed is available.