The short answer is that "C++" is only C but "plus plus" , well not taking it literally C++ is only an extended version of C.
As far as I know you can do anything you usually do on C, on C++... but not vise versa... (well at least not word by word).
C++ was mainly built to extend the functionality of C.
The main difference between C and C++ is that:
C language is procedure oriented language, it does not support OOPS concepts such as classes, objects, Inheritance, Polymorphism, Data hiding, etc.
While C++ is an object oriented language, C++ supports classes, objects, data hiding, polymorphism, Inheritance, abstraction, etc.
That's the general concept difference between the two languages...All other differences that could be mentioned are only details of what each concept has to offer.