C++ is a higher level, "object-oriented" language more suited for user-interface intensive applications. C is a lower level "procedural" language more suited for hardware interfacing applications. C is also the foundation of many higher-level languages, including C++.
But it should be pointed out that williamhemswort's link is one of those articles about "why <my favorite language> is better than all the others"
some wild-eyed zealotry? probably not; C++ is a solid general purpose language. I'd say it's just a bit of biased overenthusiasm. But whatever, programming languages are tools. nothing more, nothing less....
like any tool, use the best one for the job. Just because you can pound some nails in with your world-class wrench, doesnt mean you should