I Just Learned Something...Need To Learn How To Connect

I just learned XML. Anyone have any sites where I can learn it fully? Is it me or is all I see just some basic tags like:

<?xml version="1.0"?>
            <title>AS Bible</title>
            <title>FMX Bible</title>

…I don’t get it…is that all it is? Like in PHP there are stuff like operators, function and all. Are there stuff for XML? I’m confused as hell. Oh yea, one more thing, how do I use XML with flash?