When we discuss electronics, we are talking about generally small circuits using small amounts of electricity. These circuits handle electricity that is of lesser power by a great margin than that coming out of your wall outlet. Suffice to say, we won't be talking about residential electricity here. Instead we are concerned with small electrical signals used for sending information on the low end, to at the most enough electricity to spin a motor on the high end. To facilitate this conversation, we will start with a basic circuit to build from.
The image in Figure 12-1 shows a very simple little circuit.