Many diff are there : >Structure in C defines as limited to within the module and cannot be initialized outside but Structure in C++ can initialize the objects anywhere within the boundaries of the project. > C++ have a many methods((Procedures) but in C no methods are there. > By default C structure are Public and C++ structure are private . > C does not support Methods inside structure but C++ does. > In C++ structure we can add functions but in C structure we can't. > In C++, structure behaves like class like can add function, and can use properties on class as inheritance, virtual,etc, But in C, structure we can have only data member but not functions. > Structures in c++ doesnot provide datahiding but a class provides. > classes support polymorphism, But Structures don't.