For those not comfortable with electricity. I have found this to be helpful: Think water! OK, now, Volts is like pressure. Current is like volume. Resistance is like a kinked hose. Little kink is like a small resistor, tighter kink is like a bigger resistor. Watts? Like how much work can be done. Big hose=big volume=big wire and of course a little AWG number. Little hose= little wire and a big AWG number. AWG? American Wire Gauge. Current and Amps are the same thing. And yes all these things are related to each other. That is why the P=I times E thing works. P is Watts is work. I is current is amps is volume. E is Volts is pressure. And if you need to know E is "electromotive" force. Is this helpful? Smile and enjoy. Some one will want to talk about BMEP and Volume metric efficiency some day soon. Then some one else will have the information and I will get to listen.

Steve H