•( I ) Current is what flows in a wire or conductor like water flowing through a pipe. Current is measured in (A) amperes or amps.
•( E ) Voltage is the difference in electrical potential between two points in a circuit. It's the push or pressure behind current flow through a circuit, and is measured in (V) volts.
•( R ) Resistance determines how much current will flow through a component. Resistors are used to control voltage and current levels. A very high resistance allows a small amount of current to flow. A very low resistance allows a large amount of current to flow. Resistance is measured in ohms.
•( P ) Power is the amount of current times the voltage level at a given point measured in wattage or watts.
The relationships of Current, Voltage, Resistance, and Power are given here:
A great example provided by Jason can be found Here