Fountain of Knowledge

I know, I know - we've already done fantasy. But I want to dig deeper today. Mostly for my own edification because there are things I'm curious about.

There are lots of different sub-genre's of fantasy, including but not limited to: high fantasy (which I believe falls into the same category as sword and sorcery), urban fantasy, paranormal, etc, etc.

To me, fantasy on a general level is a story in which fantastic things happen. But to be that generic is a little deceptive (I suspect, anyway) to fans of the different sub-genres.

So...what makes each sub-type stand on its own? High fantasy - does it have to be elves and wizards and swords and dragons? Urban fantasy - you'd think from its name that it would take place in an urban setting, but does it have to? Is each that strictly defined, or is it more of a feeling that a piece gives off that makes it fall into that category. What makes something paranormal instead of urban fantasy?

And are there other sub-types I'm not mentioning?