Definition: The ratio of working power to apparent power. Power factor tells you how efficient your power usage is.
Let’s say you stop by your favorite coffee shop and order a cappuccino. The coffee portion represents the real power (what you wanted).
But, when you order the cup, you also get a bit of froth at the top. The froth represents the reactive power, or the work it took to create the creamy cappuccino.
Those two things combined represent the apparent power and you have to pay for all of it (not just the coffee).