The way I look at it is, the site for cnet news is news.com.com (I think it's supposed to mean that the "name" of the site is news.com (because it's tech-oriented), and then a .com is added at the end to make it into a domain name, i.e. news.com.com). Technically though, news is the subdomain, and com.com is the domain. Naturally, typing in com.com would take you to the same domain as news.com.com.