Short for weblog. Blogs originally had purpose when the few people who had them actually had interesting and/or informative things to say. These blogs still exist, and are quite enjoyable to read, however the advent of blogger.com and livejournal.com has changed this once meaningful application into utter shit, allowing every day idiots to write about how shitty their lives are and why everyone should care.
Good Blog: Informative news, real humor and entertainment. Often build and published by someone with a brain.
Bad Blog: "School sucks", what you had for lunch, why your depressed because your 14 year old boyfriend dumped you and its the end of the world.