[The original version of this is still available online here]
Terminology and OriginsBlog is a shortened form of the phrase web log. Blogging is the verb for maintaining a web log. A blogger is a person who creates and maintains a web log, and is also the name of a popular blog creation tool (http://www.blogger.com).
A blog is presented in reverse chronological order, updated regularly, and usually generated by special blogging software (see below). The content could be anything along a wide spectrum, from online personal diaries to the posting of interesting web resources with no commentary. In my opinion, the blogs most useful for librarians lie in the middle of this spectrum pointing to information on other websites and blogs while providing comments and opinions about this information. (See also http://www.llrx.com/columns/notes46.htm)
Blogs have been around since the early days of the World Wide Web, but were not noticed by the mainstream media until 1999. Since then, the popularity of blogs has grown steadily. There are many good accounts of blog history on the web, including http://www.llrx.com/features/lawblog.htm and http://www.salon.com/tech/col/rose/1999/05/28/weblogs/index.html.