[phyllotaxis]

Analogy. If you can make the various components of software design relatable to components of a familiar machine, like a car for example, where your programs are described as the engine, transmission, axles, tires, windshield, paint, and so on, you will have clearly explained the role of the software in the big picture, which is far more valuable than its technical specifics- in a more intuitive way. (at least to someone that has only cursory interest in the back-end aspects of program components.) Just a thought.