What's a blog?

Back when `blog' was a new term, I asked a few people what it was. The most informative answer I got was something like, it's a weB LOG, with a strongly implied `like, duh, are you an idiot?'.

I still haven't been able to figure out just what a blog is. It's clearly more than just a Web-accessible log of (part of) one's life, or people wouldn't be so babbly about blogging `packages' and the like. But nobody seems able to tell me what it is.

Not that it really matters. But that's why I'm not calling this a blog: I do not expect it to meet people's expectations for a blog. Even though I've yet to find anyone who's able (and willing) to elucidate what those expectations are, I feel reasonably sure some of them are things I am not interested in setting up; more are things I am not competent to set up. I've written a small ramble on the details.