Both digital and analog components

*Voltage* is the electrical potential. It is similar to water pressure in a
pipe. Voltage is polarized, and relative, therefore it is often measured with
respect to the earth, or *ground*. A parallel circut always has the same
voltage across all components.

*Current* is the flow of electricity. It is similar to water flow in a pipe.
Current is not polarized, and not relative. A series circut always has the same
current across all components.

These two are related via the following equation (Ohms law):

V = I * R

Where V is voltage (Volts), I is current(Amps), and R is resistance(Ohms).

Power is Voltage times Current and is measured in Watts (W). Power is a rate upon which electrical energy is used.

Also see