A lot of burners who otherwise never needed to think about electricity are forced to deal with it in BRC and have asked for help understanding the terms that always get tossed around.
I figured since almost all burners ARE familiar with riding bicycles, I'd try to draw a clear, non-technical bicycle-to-electricity analogy. (I already did this in another thread but electricity comes up so often I think it should be it's own topic.)
The books will tell you Volts x Amps = Watts... but what the hell does that mean?!
You can think of Volts as the electrical equivalent of speed, and Amps as the equivalent of force.
Lets say you're on your bike, going 10 MPH across the playa with a basket-load of fresh ice in first gear - you're pedaling really fast but with low effort. That's kinda' like high Volts and low Amps.
Now switch into 10th gear, carrying the same load at the same 10 MPH. Now you're pedaling hard, at a slow pedal speed. That's similar to a lot of Amps at low Volts.
WATTS is the amount of work actually being done. That's the bike hauling your ice across the playa at 10 MPH. Either high pedal speed and low effort (like in first gear) or low pedal speed at high effort (like in 10th gear) would both result in you and your big ice moving toward camp at 10 MPH.
The POWER (Watts) is the same in each situation described there. High pedal speed x low effort (like when in first gear) = bike moving across playa at 10 MPH.
Low pedal speed x high effort (like when in tenth gear) also = bike moving across playa at 10 MPH.
That's why the formula says Volts (pedal speed) x Amps (pedal effort) = Watts (bike hauling ice).
120 volts x 10 amps = 1200 watts.
12 volts x 100 amps also = 1200 watts.
Lets say you hit a soft silty patch of playa on the way back to camp. To maintain 10 MPH, you need more power (Watts).
You can get it by pedaling the same speed (Volts) but with more effort (Amps).
You can also get it by pedaling faster (more Volts) at the same effort level (Amps).
Both result in more Watts (bike working harder to haul ice through soft patch of playa).
Here's the deal about wire size vs. power being sent through it.
Proper wire size (gauge) is determined more by Amps than by Volts.
Back to that bike pedal crank - if you had a skinny, weak pedal crank but stayed in first gear, you'd have to pedal fast but not very hard. The crank probably would hold up.
If you shift into 10th gear and pedal slowly (low Volts) but push really hard (high Amps), you'll likely bend or break the skinny crank.
That's why Amps determine the necessary wire size, and why the same wire can carry more power at higher voltage/lower amps than it can at lower voltage/higher amps.
That's why the 12-volt battery cable in your car is HUGE wire, but the 120 volt wiring in your house isn't so fat.
About getting shocked: High Volts tend to zap you a lot more than high Amps. You can grab both terminals of your car battery and feel nothing at all... that's only 12 Volts, but a car battery can supply hundreds of Amps!
But touch the terminal of the spark plug wire, even the one on your lawn mower engine, and it'll zap the hell out of you. The engine's "coil" converted the 12 volts way up to several thousand volts, but at low Amps.
My analogy: Someone is pedaling REALLY fast (high Volts). You stick your hand in the way of the pedal. It whacks you!
Now lets say someone is pedaling REALLY hard, but very slowly. Stick your hand in the way of the pedal - doesn't hurt!
There are some gross oversimplifications in these descriptions; if anyone wants to elaborate go for it, but the idea is just to help people who don't understand electricity at all, and don't want to, understand the terms being thrown at them as they try to figure out their camp power logistics.
Too much is not enough, and when in doubt double it.