Difference between watt and volt-amperes

Although we can't necessarily see electricity, we can measure it by its effects. An ampere, or amp, represents the amount of current in a circuit. Voltage is defined scientifically as the circuit's "potential difference," and can be seen as the amount of "pressure" that drives electricity in a circuit. Watts are a measure of the use of electrical power, and one watt is equal to one volt multiplied by one amp.

The watt is used to measure an AC circuit's true power, whereas a volt ampere is used to measure the circuit's apparent power.

Apparent power is the product of current and voltage, whereas true power is the product of current, voltage, and power factor.

The true power of an AC circuit is measured using a wattmeter, whereas the apparent power is the product of current and voltage.