Apparent power

Apparent power: In alternating-current power transmission and distribution, the product of the rms voltage and amperage. Note 1: When the applied voltage and the current are in phase with one another, the apparent power is equal to the effective power, i.e., the real power delivered to or consumed by the load. If the current lags or leads the applied voltage, the apparent power is greater than the effective power.

Note 2: Only effective power, i.e., the real power delivered to or consumed by the load, is expressed in watts. Apparent power is properly expressed only in volt-amperes, never watts.

Source: from Federal Standard 1037C