This 2 minute safety training video covers: What is current, how is electricity measured, what deliver electric shocks, what is amps, volts and watts, how to determine or compute how many amps to be used.
The electromotive force cause by generators is really electrical pressure measured in units called volts. When a switch is turned on and electricity begins to move its rate of flow called current measured in amperes, more electrical pressure higher the voltage usually causes more electrical current to flow, higher amperage. Like water pipes, electrical pathways or wires tend to impede or resist the flow of current. If the electrical pressure stay the same the rate of current flow or amperage changes depending on the size of the wire. A long thin wire causes more resistance a wire much thicker causes less resistance thus more current flow. The exact relationship between pressure, flow and resistance can be calculated mathematically.