In the definition of AC circuit, active power is the average power.
In an AC circuit, the average value of the instantaneous power emitted by the power supply within a cycle (or the power consumed by the load resistor) is called "active power".
Or:
Active power - the electrical power required to maintain the normal operation of electrical equipment, that is, to convert electrical energy into other forms of energy (mechanical energy, light energy, thermal energy) The electrical power is called active power; also called average power.