Voltage is basically the difference of electrical potential between two points of an electronic circuit. Measured in volts, it is the potential energy of electric current.

One way when voltage is used is to specify the voltage of a point in a circuit. This is the voltage difference, the reference point being referred to as the ground.

The more common instance where voltage is used is to determine the amount of volts that are traveling in an electrical device. It is the first voltage taken, relative to ground, on one terminal subtracted to a second voltage on another terminal. A voltmeter can be utilized to measure voltage in this manner.

Other instruments that are used for measuring voltage are the potentiometer, and the oscilloscope.

Computing for voltage is basically the addition of all current running through a device. The formula for voltage is v=i*r, where voltage is equal to the current multiplied to the resistance.

Direct current is the sum of instantaneous voltages. Alternating current, on the other hand, is the difference between instantaneous voltage and average voltage. Average voltage can be taken from signals if they have the same frequency.