Many websites have links labeled "XML" or "RSS" or "Atom". All of these are ways of saying that you can find out about updates to that site without having to visit the site in your web browser.
This feature is referred to as "syndication" or "aggregation". Sometimes it's just called subscribing. And these days, instead of one of these words, lots of sites will use a little orange button.
The standard one looks like this:
It's also common to see buttons that say "RSS" or "XML".
All these links and buttons mean the same thing: The site you're viewing has a feed available.
How do I read an RSS feed?
There are a variety of tools available to read the contents of an RSS feed. Such tools are called feed readers. These tools lets you subscribe to any feeds you want, check automatically to see when they're updated, and then display the updates for you as they arrive.
Feed readers can run on your computer or you can sign up to use a feed-reader that runs on the web. If you use one of the web-based readers, you can access your feeds from anywhere you go, just by signing into the website that manages your feeds. If you use a feed reading program that installs on your computer, your feeds can be stored for you even if you're not connected to the Internet.
How do I get a feed reader?
There is a range of different feed readers available and new versions are appearing all the time. Different feed readers work on different operating systems, so you will need to choose one that will work with your computer.