Twelve sections, two dozen concept pairs — grounding vs. bonding, real vs. reactive power, delta vs. wye, fault current vs. arc flash, and more — each worked with a concrete example and the exact confusion it resolves in the field.
Module 2 covered what electrical components are. This module covers why they behave the way they do — the conceptual distinctions that separate someone who can identify a breaker or a transformer from someone who can predict how it will actually behave under a fault, a motor start, or a design change. Every one of these pairs gets confused constantly on real job sites and in real design reviews, and every one of them has a concrete, practical consequence when it's gotten wrong.
This is the hallmark module of the entire program. Everything from Module 4's drawing symbols through Module 10's troubleshooting scenarios and all nine real-project case studies leans on the distinctions built here — grounding vs. bonding surfaces again in Module 6's code deep-dive, fault current and arc flash return at full scale in the Module 12 substation project, and sourcing vs. sinking I/O comes back concretely in Module 9's controls wiring.