Well, I don't want to confuse you by mixing together all these terms that I'm not that familiar with so I'll just ask in plain english:
I have a personal blog page, created with PhP and using MySQL database. Since RSS is getting so popular I want to offer my friends and other visitors to add my blog to their RSS aggrigator, like My Yahoo and the upcoming Outlook 12 etc. etc.
I page include a few categories, like personal blogs, picture galleries and video clips and I like to make a separate RSS feed fo each of those categories.
All right, I knew it had to be simple, but not all that simple ;)
So, I actually let the php code that "creates" the .xml file decide e.g. how many posts the feed should have and so on...? isn't that right?
And when the .xml file is complete, everybody that has an aggregator that support RSS 2.0 (or whatever I decide to use) should be able to use it just by linking to the file? (i.e. they don't need any other file or some info to use it, right?)