What is RSS and what is it for?

RSS (Really Simple Syndication) allows users to subscribe news or regularly updated content from websites supporting this technology.

The user subscribes the RSS Feed on an application called Aggregator, desktop app or web app, which automatically refreshes subscribed content. Aggregators allow you to subscribe news from several websites, confortably centralizing all your daily reading in one place.

All the great news websites like CNN, Reuters, Wired, have been using this technology for some time and cast their news through RSS.

 There's no need to open several webpages and visit the websites regularly.

 How to identify websites with RSS?

So far only few browsers indicated the awareness of RSS on a website like Mozilla Firefox, but now Microsoft Internet Explorer 7 also has that ability. The most popular icon for RSS is and usually shows up on the address bar or on a toolbar whenever the website we're on has RSS. If you click on that icon, a dialog window will show up so you can choose the service or application to subscribe that feed.

Aggregators

There are several RSS Aggregators, that you can download and install on your computer, or as a web based service.

 Desktop apps:

RSS Bandit (Free, Windows)
FeedReader (Free, Windows)
NetNewsWire Lite (Free, MacOS X)
Vienna (Free, MacOS X)
RSS Owl (Free, Multiplatform)

Online services:

NewsGator
GoogleReader
Netvibes
Bloglines

For more informations on RSS and Aggregators see this article on Wikipedia:
http://en.wikipedia.org/wiki/RSS