Facilitator or Helper Classes

A facilitator or helper is a class that helps process a service, but does not hold the data values or do actual work itself.

An example found in many graphical user interface libraries is a painting assistant, such as a Pen or Canvas, that provides the tools needed to perform graphics operations, but does not itself know what operations need to be performed, nor the final display technique.

[audio] [real] Text to accompany slide14, in Chapter 3 of An Introduction to Object-Oriented Programming