What exactly is the deal with XHTML?

[Allstories]

I learned HTML when I was 9, like 6 years ago, from sites like Lissaexplains.com and books I ordered at school. Now I keep hearing about all this XHTML stuff. I'd like to know out of curiosity how important learning XHTML would be, and how hard it would be and how different it is from traditional HTML. I don't know which 'version' of HTML I know, but I haven't drastically expanded my knowledge in the 6 years I've known it. Also, I've read stuff about XHTML 2.0 being a whole new language beyond a mere update, so I'd also like to know if NOW is the time to be relearning stuff.

[Dragonfree]

Well, there's stuff like that you must type tags in all lowercase and tags that don't have a closing tag have to be closed with /> at the end, like <img src="blah" alt="Oh, and the alt attribute is required for all images" /> or <br />. (Don't forget that space.) Don't really remember any other main differences; it's not hard to switch at the very least.

[Kipkip]

XHTML is just a more strict version of HTML, basically. Never heard anything about XHTML 2.0.
EDIT: XHTML 2.0 seems to be a more structured format and not backwards compatible. It also seems to have better intergration with XML and CSS. It's what blogs use.

[pokejungle]

Doesn't everyone use lowercase tags anyway? :P

All I need to change is my <br> 's into <br /> I like the first way better though =/ My img tags need to be changed too I suppose

[Chaos]

Doesn't everyone use lowercase tags anyway? :P
Check your website's code. Plenty of UPPERCASE tags in it.

[Thomas-san]

Here is what my (X)HTML/CSS book says about XHTML:

Sorry the scan kinda messed up:
http://img163.imageshack.us/img163/9836/scan0010016bz.jpg

[pokejungle]

Check your website's code. Plenty of UPPERCASE tags in it.

You'll notice that that's the layout that I didn't make. Once I got XHTML I have to get a new layout.

[Chaos]

Or you can just work through it and change it yourself... find and replace the common tags and attributes (with case sensitive searching on), and then just skim it over for the rest that were missed.

Just because you didn't create a layout doesn't mean you can't modify it. Especially for something as simple as case changes.

[PichuSecretBase]

I don't see why XHTML is really nescesary. Does it affect load time? If it does then I'll consider it but if not, I don't see a point to it. Though XHTML looks better then HTML XD.

[Haruki Hanai]

XHTML is more extensible than plain and simple HTML. Yet XHTML 2.0 eliminates presentation elements like <b> and <i> and <img>... so it depricates unnecessary elements for elements like <strong> (which is like <b>), <em> (emphasis, like italics) and <object> which makes better use of displaying objects.

[Geometric-sama]

XHTML is a bridge between standard HTML and XML. At the moment, all browsers still read HTML, so you don't need to worry much about XHTML. However, in the future, XHTML will be the standard. XHTML is more strict than regular HTML, but if you want to keep webmastering you'd do well to learn how to code in it, or at least set Dreamweaver to make your pages XHTML-compliant.

[pokejungle]

I miss the short takes like <b> and <i> ;o;

What's the line tag?! Isn't it like <l>text</l> or something? oo;

[Haruki Hanai]

<line>Like this.</line>

Oh c'mon, <em> and <strong> are easy to use.