I would say one of the major differences between your typical web site an a blog is that a blog is presented in an “editorial” format that really puts the focus of the site on the author ideas and opinion, versus strictly content and fact(oids) of your typical website. One benefit I find with Blogs is the information tends to be more up-to-date due in part to the nature of blogging itself, whereas your average website is more likely to have static content.