Why do I need XML?

Why xml?? well from what I know its a markup language that you can intergrate with other languages. For instance there are alot of new database applications that can create a 'not hassle' database simply by coding you documents in xml,what happens is the database automatically pulls the necessary info from your code to classify it. Encryption is also possible. For more info check out
http://www.w3.org/XML/

To answer your questions, technically, it can be both client & server side, I don't know for sure but I think IE 5+ and NS 6+ support it.

Why should you learn it?

1) Job Security
2) It has great potential as a "universal data standard"
3) Learning new stuff is fun...

Seriously though, it is excellent as a data translator, useful for sitting between 2 legacy systems and converting data into the proper format for each. This can also be achieved through hard coding a solution, but in theory the XML solution could be applied anywhere whereas the hard coding solution would only work for that case.

What scares me a little though is people are using XML just for the sake of using it, when it would've been simpler and more efficient to do it another way.

I started getting into XML when all of a sudden the book I was learning from spent 5 pages of code to display a seasons worth of baseball statistics. These could be filtered, sorted etc.
But the coding time - it appeared to me to be too much. I can do the same thing with a populated db and asp etc in how many minutes?!.
Surfice it to say I put the book down and haven't picked it up again.....

Suppose I will next time I am changing jobs!

detox, that's exactly how I feel.

Peter, so XML suppose to be easier than using another server side language movie information between two dfferently structured DBs. Did I understand that right?

In reply to your 3 points:
3) I like learning new stuff, I just don't want to waste time learning something that won't help me in any great way.
2) You mean like SQL and DOM?
1) I guess I can see that.

You understood it right, the problem with SQL is that all the different database servers implemented their own custom systems. Transact-SQL is still universal at it's core, but hardly anyone uses just plain Transact-SQL in their stored procs anymore, they use advanced commands that are part of their database system. Unfortunately this makes it hard to port to other systems. Hopefully this won't happen with XML.

XML is a popular "technology" (if that's what it's called) because it offers a standardized method of storing information in a structured format.

And because it has such structure, it is relatively easy to parse. And there are no hideously unclosed tags like there are in HTML. (Sigh, unclosed tags are for fools.)