Do a quick search on the web for content management systems and you will see that there are thousands out there, and most of them are free. Almost all of them have the basic features necessary to run a blog, but not all of them are designed specifically with blogging in mind. Is any one of them sufficient for general blogging, or is there an advantage to using a CMS specifically designed for it?
Probably the most popular blogging platform these days is WordPress. It is made for blogging before anything else, although it does have other general web content management features. Because it is designed specifically for blogging, it has features such as content spam filtering and trackbacks built into it. It also supports a plethora of plugins, many of which are catered to bloggers.
Other content management systems may also have blogging features and may even have plugins designed to support blogging. Many also have features that a CMS like WordPress would not have, such as robust e-commerce support out of the box.
Ultimately, the CMS you choose largely depends on your needs. If blogging or news publishing is your primary goal, WordPress or another blogging platform with similar features would be better. If, however, you have other goals for your website that take precedence over blogging, you may be better off using a CMS that can more easily accommodate those goals. If you need both, it is very common to use more than one CMS to meet a variety of needs.