From The professor:
IoT devices involve a combination of software and hardware. This module provides background on the basics of hardware design and wiring needed to build useful circuits. This module describes the functions of basic passive components and describes how to use them in simple circuits. This module also describes how to wire circuits together using a breadboard. The goal of this module is to enable students to design and implement the circuits they need to interact with basic sensors and actuators.
Here is a cheat sheet of symbols often found in schematics and their meaning: