The RSS accronym stands for different things.
- Rich Site Summary (RSS 0.91)
- RDF Site Summary (RSS 0.9 and 1.0)
- Really Simple Syndication (RSS 2.0)
Overall, it's just an XML schema. What it does is tags the meta data for your blog, including the most recent posts (usually 10). Everytime a new post is made, it's added to the top of the RSS feed, and the oldest post in the list is pushed off.
RSS 2.0 example
<?xml version="1.0"?>
<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
<channel>
<title>Walker Art Center</title>
<link>http://walkerart.org</link>
<description>WAC RSS Test Feed</description>
<pubDate>Thu, 16 Mar 2006 01:43:06 +0000</pubDate>
<generator>http://wordpress.org/?v=2.0.1</generator>
<language>en</language>
<item>
<title>News of today</title>
<link>http://walkerart.org/news_today.wac</link>
<description>All you need to know about RSS</description>
<pubDate>Thu, 16 Mar 2006 01:29:01 +0000</pubDate>
<dc:creator>Brent</dc:creator>
<category>Lectures</category>
</item>
</channel>
</rss>
What's It Used For?
The real power in RSS is when you combine it with news aggregators. An aggregator is a stand alone app, a browser, or a 3rd party website that will check the RSS feed for updates automatically. More on this here.
RSS Formats
The power behind RSS is that it's a standard format...well almost. There have been changes to the RSS format over the years by various groups.
As you saw above, the name RSS means different things, and for each name comes a slightly different XML schema. To add to the confusion there is also something called ATOM that is basically similar to RSS 2.0, but with a few tweaks.
The good news is that regardless of the RSS spec you choose, most news aggregators will be able to read your news feed.
Creating an RSS Feed
The other good news is that just about every blog software comes with automatic RSS creation built in. Very little needs to be done other than publishing one's blog. Updates to the RSS feed happen automatically.
However it is possible to update your RSS feed to add or remove certain elements. For this you would need to read and understand the RSS spec that you chose. RSS specs are at the following links:
Broadcasting Updates
Most people use news readers to check your RSS feed for updates. Thus, if you post now, someone may not see your post for several hours (or days) if they're news reader is not set to check very often, or it is closed. But there is a faster way to disseminate updates to your RSS.
Many blogging apps have a pinging feature. This will ping a website like weblogs.com as soon as you make a post and alert that site immediately that something new is available. Sites like weblogs.com are used by many other sites and search engines (such as Google) to get the most up to date news indexed as fast as possible.