Basic Definitions:

• Subprogram Definition - the interface to, and the actions of the abstraction.
                                    (pass parameters to get interface, the abstraction means solving for small problems)
• Subprogram Call - explicit request to execute the subprogram.
• Subprogram Header - the first line of definition.
                               (define formal parameter and return value, e.g. C++ has void, int,... return data types)
                               (e.g.      SUBROUTINE ADDER(parameters)        FORTRAN
                                           procedure ADDER(parameters)           Ada
                                           void adder(parameters)                      C)
• Parameter Profile - the number, order, and types of formal parameters.
• Protocal - profile and return type.
• Prototype - In C++, a function prototype tells the compiler the type of data returned by the function, the number of parameters the function expects to receive, the types of parameters and the order in which these parameters are expected.  The compiler uses function prototypes to validate function calls.