According to Wikipedia:

RSS is is a family of web feed formats used to publish frequently updated works-such as blog entries, news headlines, audio, and video-in a standardized format. An RSS document (which is called a “feed”, “web feed”, or “channel”) includes full or summarized text, plus metadata such as publishing dates and authorship. Web feeds benefit publishers by letting them syndicate content automatically. They benefit readers who want to subscribe to timely updates from favored websites or to aggregate feeds from many sites into one place.

As one of our clients put it, “you lost me at ‘web feed formats’ can you start over?”.
If you have a blog, this is all fairly important and if you use our services here at Widget, you’ll end up calling us to ask “where is my RSS feed” at some point, so pay attention!

Think newspapers. Syndication is quite simply broadcasting (an article or cartoon) for publication in many magazines or newspapers at the same time. Ironically, now this term is more often used regarding the content of websites than it is for newspapers.

Really simple syndication comes set up and ready to go on most blogs. On Blogger, for instance if you type in http://blogname.blogspot.com/atom.xml the “feed” will usually automatically come up. That is, if you haven’t changed settings, but we’re assuming here you’re a beginner and you don’t go regularly mucking around in your publishing settings in the back end.