I'm curious this looks like a feed of some kind but I'm still un sure as to what it really is and does.

Hey Ed, :)

Ok first of all:
XML = eXtensible Markup Language
RSS = Real Simple Syndication
SGML = Standard Generalized Markup Language

RSS is a form of XML.
The reason people like XML so much is that its so customizable. There's no predefined set of tags to stick to. XML is a subset of SGML as is X/HTML.
Now since XML tags are so customizable, they are easy to parse. So if you had an XML file that contains some data, you could use something like either PHP or even Flash (I believe both of them have built-in XML "capabilities") to parse the XML and output the data as plan text, formatted or not.

Some examples for this flavour of XML:
1) If you use KlipFolio from serence (http://www.serence.com/site.php), you will notice that it gets the latest news by itself. The Klip (http://www.klipfarm.com/farm.php) actually updates itself via an RSS, RDF or some other XML format files that contain the actual data. Most forums have an XML feed.

2) I created a little script recently that has a link titled "Update" in the admin panel and that link, when clicked, parses an XML feed on my site and compares the version number in that XML file (which I update with the latest version number available) with the version number within the script itself. This will tell them if they need an update or not.

RSS is a subset of XML
XML is a subset of SGML
X/HTML is a subset of SGML

There's a whole bunch of other XML formats similar to RSS.
Here's a bunch of links for RSS (http://www.google.com/custom?q=RSS&sa=Go&cof=T%3Ablack%3BLW%3A72%3BALC%3A%23ff3300%3BL%3Ahttp%3A%2F%2Fwww.w3.org%2FIcons%2Fw3c_home%3BLC%3A%23000099%3BLH%3A48%3BBGC%3Awhite%3BAH%3Aleft%3BVLC%3A%23660066%3BGL%3A0%3BAWFID%3A0b9847e42caf283e%3B&sitesearch=w3.org&domains=w3.org)