Here is what I think it means. The cycle starts at the baseline, heading up. Presumably, a baseline day is medium. I think it would be quite difficult to draw cycles, knowing what you know now. The class names are Button, Graphics, and String.
Every object is a member of some class.
That class is in its own file. So, one program may be spread out over several files, as it bounces from place to place. We have just started to write object methods in class. Actually, when we were writing applets we were writing object methods, but we didn't know it then. An object can have public methods and private methods.