For feeds from Vistua, see Main.Rss, for a practicum see "Syndication How To"
Standard Feed Icon
Web Feeds is a generic term used to refer to various kinds of very similar technology for syndication of site content. The most popular of these technologies is RSS, "RDF Site Summary". The "Atom" format is also occasionally used.
RSS and ATOM both use the XML (eXtensible Markup language) developed by the W3C (World Wide Web Consortium). This allows developers to easily write software that supports both. Using the XML markup, feeds contain summary information about sites, such as text from new articles on the sites which is downloaded by a feed reader and rendered into a human readable format.
This in itself would not be terribly useful, however the key to web feed syndication lies in aggregation, (which is why feed readers are occasionally referred to as "aggregators") the compilation of these feeds into a single, (usually) chronological source.
This is similar to how local newspapers work. Because these small papers cannot afford to maintain dozens of foreign bureaux to cover global affairs—or may lack specialized journalistic expertise needed to cover topics such as the arts and sciences, they have two options, entirely omit coverage of these topics or use syndicated "wire copy".
The "wire copy" is written by a "wire agency" such as the Associated Press, Bloomberg, Reuters or TASS and transmitted to the agency's customers, such as the newspaper for reproduction. In the old days, this information was transmitted via teletype, hence the term "wire copy". Other types of content such as comics, op-eds and lifestyle columns may be syndicated this way.
Similarly, feed readers accumulate content, which may include news articles, blog posts, comics and the like from a list of web feeds and present it to the viewer for consumption.
A very simple practical example can be seen below:
Simple illustration of syndication
Of course, in reality most people aggregate dozens, if not hundreds of feeds.
A very simple aggregator can be seen in action at Vistua Planet which does nothing more than aggregate together feeds from Vistua Network members.
The presence of the standard feed icon indicates the availability of an RSS or Atom feed, some pages give you a choice, it doesn't matter which you choose, they are of a muchness.