A blog is basically a journal that is available on the web. The activity of updating a blog is "blogging" and someone who keeps a blog is a "blogger." Blogs are typically updated daily using software that allows people with little or no technical background to update and maintain the blog. Postings on a blog are almost always arranged in cronological order with the most recent additions featured most prominantly.
Who woulda thunk it??
Brian
AwPhuch