If you've reached this page you might be wondering what Atom XML and RSS are, or what the strange orange icon represents.
The icon is the standard way of showing that a website has XML feeds available. But what are XML feeds?
The best way to describe them is by an example. You can find out what's new on this site any time by visiting it - opening it up in your browser and typing the address.
If you've only got a handful of sites you regularly visit, that's pretty easy. You might visit a few that haven't been updated, but you can get away with it.
If however you visit quite a few sites regularly, that is a bit less easy. So someone came up with an idea. What if all the site owners (i.e. people like me) wrote a simple file which had details of the latest updates. Then what if there was a little programme that put all those files available to you in one place - you open that place, and see in one go, what's changed and what's not? And what if that programme was a little clever and only showed you things that you haven't seen before, and hid the stuff you've read?
Someone thought it was a good idea and the concept spread. That little programme is called a Newsreader or Aggregator.
Atom and RSS are two different ways of writing those little files (known as feeds), but essentially do the same thing, and most newsreaders will accept either.