C is structured programming language. Turbo C refers to a specific compiler made by Borland that can be used for C programming.
C++ is a superset of C, meaning everything that you can do in C, you can
do in C++. C++ also supports object-oriented programming through the
use of classes and inheritance.
C# is another language from Microsoft. It is similar in structure to
Java and syntactically to C++. It does not compile down to native
machine code, but rather CIL, an intermediate assembly type language.
Therefore, to run a CIL or .NET program, the appropriate runtimes must
also be installed. C# is completely object-oriented unlike C++.