This may be the wrong place for this, but bear with me.
I've been looking into AJAX recently, and while I'm familiar with some of the basics (calling a PHP script from a page and returning the results, for example), I am wondering about some of the other things I am seeing. Specifically, I am wondering if these things are even related to AJAX.
Recently in dealing with Joomla, I noticed that their templating system uses what appears to be custom tags, such as <jdoc:whatever>. I know that .NET has something similiar, as do a few of the Ruby based CMS' that I've looked at. My questions, I suppose, are:
1) What is the proper term for these tags?
2) How do they benefit the design of the framework?
3) Are they even in the same category as AJAX or am I way off base?
I am basically interested in learning about PHP/AJAX frameworks and, specifically, how to design and develop one of my own. Are these tags that I've seen part of an AJAX framework? If so, can anyone point me towards a good location where I can learn more? The web is fraught with tutorials, and I'm not even really sure what to call what I'm looking for in the first place.
I hope this makes sense. If it doesn't, then God help us all.