Class objects can be assigned (unless copying has been restricted), passed as arguments to functions, returned by functions (with some exceptions), and so on. Other operations on class objects and members can be user-defined in many ways, including definition of member and friend functions and the redefinition of standard functions and operators when used with objects of a certain class.  

Redefined functions and operators are said to be overloaded. Operators and functions that are restricted to objects of a certain class (or related group of classes) are called member functions for that class. C++ offers the overloading mechanism that allows the same function or operator name can be called to perform different tasks, depending on the type or number of arguments or operands.