@Quercus great summary. Its not necessarily an easy topic for a beginner book, however one that is really important IMHO to gain competence. Its also a diffeent model to other languages (that I’d used in the past). I think it was a good post on SO that cleared it up for me, and I recall seeing some diagrams too - will see if I can dig up the reference.
In the meantime, here’s a great example of all 100 mistakes in one script!