What is the difference between C and C++?

C++ is a direct descendant of C that retains almost all of C as a subset. C++ provides stronger type checking than C and directly supports a wider range of programming styles than C. C++ is "a better C" in the sense that it supports the styles of programming done using C with better type checking and more rotational support (without loss of efficiency). In the same sense, ANSI C is a better C than K&R C. In addition, C++ supports data abstraction, object-oriented programming, and generic programming.

I have never seen a program that could be expressed better in C than in C++ (and I don't think such a program could exist - every construct in C has an obvious C++ equivalent). However, there still exist a few environments where the support for C++ is so weak that there is an advantage to using C instead.