What is a blog?

“blog” is short for “weblog” or “web log”
It was originally a way for people to document the interesting sites they found on the web, so they were originally just a list of links with some description.
Then the metajournalling craze caught on and blogs became something more interesting – not just “I went to work today” but much more thoughtful and interesting writing.

Salam Pax the Baghdad blogger was essential reading during the Gulf War as he described waiting for the invasion, the Americans arriving, and the aftermath. His blog has been made into a film.

Bloggers have been sacked from their jobs for referring to work matters – notably an air hostess who posted slightly (but not very) saucy pictures on her blog in uniform. Blogs containing a lot of video and photographs are called vlogs. Blogs can be used as student journals, to record their reading and progress of their projects, either privately, or for their tutors to look in on. Academics using blogs, from the BBC:
Authors use it to keep their readers up to date on how their books are coming along, what they’re thinking and writing about, and where they’re appearing. William Gibson’s blog

Because of the features allowing several people to own and post to the same blog (“group blog”), and the comments feature enabling anyone to post a comment at the end of a piece, blogs have become the centres of communities and a very real replacement for (some) forums.

One of my favourite blogs recreated Pepys Diary daily, in real time as it were.

There are also web memes, for example where everyone writes a version of the same thing in their blog – such as five things I want to do before I’m fifty.