Method is another name for C++ member functions.
Methods may be constructors, destructors, functions, and overloaded operators.
Methods define the class interface. (The constructor and overloaded plus operator in Listing 3 are methods.)
A message is the invocation of a method. In C++, this is the same thing as calling a public member function.
The program sends a message to an object telling it to execute the method.
Sometimes parameters are provided for the method to use.