Hi Deon
CB Articles displays on users profile Joomla OR K2 articles that a user has written eighter from backend or from Insert Article menuitem in Front end.
Configuring the plugin you can select source and exclude some categories. You cannot insert new article form your profile.
Cb Blogs on the other hand can handle, apart from Joomla OR K2, its internal catergories (indipendedly)
Can be configured to ask aproval, can use Captcha and can be set to delete all users articles if deleted from your site.
In other words CB Articles and CB Blogs are very much alike but Blogs have more options to choose from.
You can use both e.g if you want to display separetly articles from different categories.