Power factor (PF) is an important component of an alternating current (AC) circuit, but understanding its actual effect can be difficult. Why is PF mysterious to many of us? It has to do with the way it is explained.
PF is often defined as the ratio of the real load power to the apparent power in the circuit. Real power is the power consumed by the circuit, and apparent power is the sum of the real power and reactive power. Reactive power is often called imaginary, phantom or borrowed power. Real power is measured in watts, and reactive power is measured in volt-amps.