RSS, usual acronym for "really simple syndication", is a short XML document website owners use to broadcast the new contents on their sites to the world. Those who are interested in being notified when these new web pages are published subscribe to the feed (which is the name by which these RSS files are known) and read them in aggregators (which is the name by which feed readers are known). Once they have read there are new web pages on-line, they can decide whether to visit the website or not, or they can even read the new pages right on their aggregators.
Using a feed
If you are a reader, subscribing to a feed will let you know when your favourite site has been updated without having to visit it now and then and look for changes by yourself. It is very convenient.
To read a feed you need to use either a web-based or browser-based aggregator; to subscribe you only need to click the orange icon you see on the right corner of your address bar. The software usually does the rest for you.
Publishing a feed
If you are a website owner, publishing a feed will help you keep your visitors happy because they will know when you update their favourite site! How to publish one? It is not that hard, just open a new file on a text editor and type this:
<?xml version="1.0" encoding="utf-8"?>
<description>A serious effort to summarize the Internet and make the world a better place.</description>
<description>Information on what is, how to use and how to publish a RSS file.</description>
You got the structure, didn't you?
The first two lines state that you are creating an XML file of the RSS 2.0 type. The next one opens your channel, which includes the general information of the feed that corresponds to the site you are publishing in three fields called title, link and description. After that, you start notifying about your new web pages as items, each with their own title, link and description. Last, you finish your XML file closing the channel and RSS tags you opened.
Once you have your feed ready, you need to save your file (using a .xml extension) and link to it from your web page. To do that, just add this line to the head section of your XHTML document:
<link rel="alternate" type="application/rss+xml" href="feed.xml" />
...or this one in the body:
<a type="application/rss+xml" href="feed.xml"></a>
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