What is a Blog?

~ (n.) Short for Web log, a blog is a Web page that serves as a publicly accessible personal journal for an individual. Typically updated daily, blogs often reflect the personality of the author.

~(v.) To author a Web log

The origins of blogging go further back than the Internet to the days of personal diaries, chronicles and other written forms of personal musings. Today, a blog is considered to be a Web page that serves as a publicly accessible personal journal for an individual or company. Blogs are typically written in chronological order and displayed in reverse chronological order to the reader. Online media, such as discussion forums and e-mail lists are also considered to be predecessors to the blog.

The word blog itself is a play on the words Weblog, as most blogs will be displayed in a journal or log entry format, where most are updated daily or more frequently than most Web sites would be. Blogs often reflect the personality of the author or the company employees they represent. To this end the most accurate and fitting evolution of today's blog comes from online diaries where the diarist would keep an online journal of themselves.

Webopedia:Online Computer Dictionary for Computer and Internet Terms and Definitions
http://www.webopedia.com/